TSG Chapter VI. Treatment of Textiles - Section I. Consolidation/Stabilization - Adhesive Methods

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• Textiles

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• Textile Specialty Group

Section

• Treatment Techniques and Procedures

Contributors: Susan Adler, Deborah Bede, Lauren Chang, Kate Clive-Powell, Lucy Commoner, Olivia Eller, Shirley Ellis, Patricia Ewer, Kathy Francis, Joanne Hackett, Mary Kaldany, Irene Karsten, Teresa Knudson, Nancy Love, Anne Murray, Jackie Peterson-Grace, Nancy Pollak, Sarah Stevens, Karen Thompson, Deborah Lee Trupin, Jan Vuori.

Introduction

This page addresses treatment steps specifically related to stabilization of textile artifacts using adhesive methods. Adhesives can be used to stabilize a textile artifact, either locally or overall. Adhesives can also be used to stabilize paint on the textile artifact, and/or decorative elements made of auxiliary materials such leather or glass. Many of the considerations outlined on the page Stabilization by Non-Adhesive Methods apply equally to adhesive methods.

The decision to use an adhesive in the treatment of a textile is exceptionally complex. Adhesive treatments are rarely totally reversible without loss or alteration of original material and are most appropriately used when other reversible or "re-treat-able" techniques are not possible. The type of textile and its size, condition, and future use must be taken into account. Developing an adhesive treatment requires balancing varied and sometimes opposing treatment goals -- support and stabilization must be balanced with flexibility and retention of the textile's properties.  Adhesive treatments often require testing with mock-ups to evaluate bond strength and visual effect.

Adhesive treatments require training with a conservator who is very experienced in the technique and selection of adhesives. Inappropriate or unskillful adhesive treatments have the potential to cause serious and permanent damage to objects. Many adhesive treatments involve solvents; all health and safety guidelines and regulations must be followed.

Definitions of terms as used on this page:

Adhesive - a substance that holds two surfaces together by interfacial forces.

Consolidant - a solution of adhesive in solvent that is used to hold together a deteriorated and friable material.

Support - the material (Stabiltex®/Tetex®, net, non-woven, etc.) that is prepared with an adhesive coating or used with an adhesive film.

Substrate - the material (glass cloth, polyester film, silicon-coated paper etc.), used under the support while preparing it with adhesive, or the material on which the adhesive film is cast. Also referred to as a casting substrate.

Stabilization of a textile artifact includes any treatments that attempt to arrest or reduce the rate of deterioration.

Consolidation - Although consolidation is often used interchangeably with stabilization, the term consolidation more accurately describes treatments whereby flaking, brittle materials are secured by impregnation with a consolidant.

Factors to Consider

Size, type, and structure of textile artifact:

• Adhered supports are most effective if the conservator has full access to the reverse side of the textile artifact to which the support will be attached.
• An adhesive with a relatively weak bond can be used to stabilize small, flat textiles that will also be mounted onto a solid support.
• An adhesive that produces a stronger bond is required for any textile where future movement is a factor. Three-dimensional textiles, such as costume, will require an adhesive that forms a stronger, more flexible bond and a support that is more conforming. Multi-layer and/or three-dimensional artifacts may require disassembly for an adhesive treatment. The presence of puckers, pleats, gathers or other types of fabric manipulation or distortion will make an adhesive treatment more challenging.
• If the artifact includes decorative elements such as beads, straw, feathers, etc., it may be prudent to consult an objects conservator who has experience with the materials in question before developing an adhesive treatment plan.
• Adhesive stabilization is not suitable for some textiles. These include very thick and heavy textiles, such as tapestries, and highly textured textiles including embroideries with floats and knots, which may hinder uniform bonding. Textile artifacts with extensive surface distortion present challenges for adhesive backings and may not be good candidates for these treatments.

Condition of the textile artifact:

• Fabric shattering and splitting often indicate deterioration due to inherent vice, which is progressive. Thus a full support should be considered even if shattering or splitting is localized. Patched or localized supports can increase stress on fibers along edges of the supports.
• Friable or powdering textiles are not usually good candidates for adhesive backing because bonds will break within the fibers with time and handling and the support will no longer be attached to the textile.
• Extremely brittle textiles may not be candidates for adhesive stabilization with an adhesive-coated support fabric because the treatment process requires considerable handling.
• Loose particulate soiling or localized stains will affect the strength and effectiveness of an adhesive bond. Artifacts should be cleaned prior to stabilization with adhesive methods.
• Adhesive residue from a previous adhesive support treatment will affect the nature of the bond.

Limitation of future analysis:

• Adhesives will almost always leave residue on a textile which may obstruct future material analysis.

• Adhesive treatments usually partially obscure the reverse sides of textiles, making them inaccessible for future structural analysis.

Adhesives Used in Textile Conservation

Only adhesives that have proven stability should be considered. Testing of adhesive formulations should be recent since formulations often change.

Characteristics to evaluate when selecting an adhesive:

• Long-term aging characteristics and stability - will the adhesive retain flexibility, and a stable, neutral pH over time? Will it yellow or shift in color? Could it release damaging degradation products as it ages?
• Bond strength and its compatibility with the object and treatment goals - does it maintain stable bonding properties over time?
• Retreat-ability/reversibility (both short term and long term) - will it remain soluble or be able to be softened by a solvent that is safe for use on the object?
• Appearance of the adhesives - glossy or matte, colorless, transparent when dry
• Flexible adhesives are preferred in order to preserve drape characteristics of the artifact.
• Tack/stickiness upon drying - the glass transition temperature (Tg) should be around 50-77°F (10-25°C). A higher Tg gives a stiff brittle adhesive coating; lower Tg results in an adhesive that is quite tacky at room temperature and an adhesive film that remains tacky may result in accumulation of particulate soiling where the adhesive is exposed.
• Ease of use - availability and time required to prepare adhesives solutions and cast adhesives films.
• Health and safety - the adhesives should be able to be applied to the artifact in a manner that is safe for the conservator. If solvents are used in any part of the treatment, suitable fume extraction and/or appropriate personal protective equipment are required.
• The adhesive should not shrink during the bonding process, and reactivation conditions (e.g. temperature, pressure) must be safe for the artifact.
• Starch and carbohydrate adhesives have a risk of attracting insects.

Adhesives Used for Textile Stabilization

Carbohydrate adhesives and adhesives in emulsions are usually diluted with water; adhesive resins are diluted with solvents. When dry, weaker solutions (10% adhesive) tend to produce coatings that partially or completely cover the yarns of the substrate. A more concentrated solution will dry to fill fabric interstices more completely, becoming more film-like. Repeated application of dilute adhesive solutions increases the amount of adhesive deposited.

• Acrylic adhesives
  • Acryloid F100 (resin)
  • Lascaux 498HV® alone or in combination with Lascaux 303HV, formerly Lascaux 360HV (emulsions).
• Ethylene-vinyl acetate copolymers (EVA)
  • Beva ® 371: available in two film thicknesses, 1 ml and 2.5 ml. It was developed for painting conservation. Wax ingredients can cause staining of textiles if used improperly.
  • Elvace® 45675

• Polyvinyl acetate resins and copolymers (PVAC)
  • Mowilith DMC2V / Clariant T1601® (emulsion)
  • Jade 403®
• Starch and carbohydrate adhesives
  • wheat starch
  • rice starch
  • methylcellulose
  • hydroxypropyl cellulose (KlucelG®)
    • A modified cellulose adhesive used in conservation since the mid 1980s. Soluble in both water and organic solvents, it creates a thin, even, flexible, and clear film but forms quite weak adhesive bonds. Tests by the Getty Conservation Institute have classed it as having intermediate stability (expected to fail in 20 to 100 years), and tests by the British Museum showed it retains its solubility upon aging and remains 100% reversible in water, IMS and acetone (Gill, p.19).

• Sodium carboxymethyl cellulose
• arrowroot starch/alginate
• funori

• Vinyl acetate-ethylene copolymers (VAE)
  • Vinamul 3252® (emulsion)

Testing to Assess Adhesive Bond Strength

Mock up testing to determine a method that gives adequate bond strength is critical for adhesive stabilization due to the number of variables involved in the treatment, differences in equipment and materials from lab to lab, and differences in conservator skill and technique. A semi-quantitative testing method has been recommended (Karsten and Down, 2005):

• Use samples of identical width to test all treatment techniques (1 inch (25 mm) is good).
• Use a continuous adhesive film on supports to test reactivation variables. The continuous film permits inspection of the degree of embedding with minimal magnification and allows easier identification of reactivation methods that create too strong a bond.
• Retest for final bond strength with more appropriate dilute adhesive solutions.
• Determine bond strength with clip-on weights (1 inch (25 mm) wide bags filled with shot to give 10 g, 25 g, 50 g, 75 g, 100 g, and 150 g) following the clip peel procedure outlined in Karsten & Down (2005).
• Research suggests that failure of a 1 inch (25 mm) wide specimen to hold a 10 g weight indicates a very weak bond. Ability to hold a 150 g weight probably denotes a bond too strong for most purposes. Moderate bond strength is characterized by failure at 50-100 g.

Casting Adhesive Films

Substrate Materials

The material, gauge, and texture of the substrate influence the qualities of the adhesive coating. The substrate must be completely smooth (i.e. free of wrinkles and bubbles), level and clean. A smooth surface texture on the substrate produces a shinier coating; a small amount of texture may make a more desirable coating for some uses. Placing the substrate over a piece of dark paper will enhance the visibility of the support, making it easier to check alignment and adhesive amounts. Commonly used substrate materials include the following:

• Polyethylene sheeting
  • Widely available in a variety of sizes, gauges, and textures. Thin gauges are preferable as creases or folds are more difficult to remove from thicker gauges.
  • Probably the cheapest substrate material.
  • May be difficult to lay out smoothly. It must be stretched and taped to the work surface under tension to remove creases, as they cause unevenness or gaps in the coating.
  • Produces coating with a medium sheen.
  • Coatings are usually easily released; release may be more difficult if the coating is dried in low relative humidity conditions.
  • Wetting the work surface then unrolling polyethylene sheeting and smoothing it with a brayer, roller or squeegee will create a smooth, wrinkle-free substrate.
  • Stretching and taping the polyethylene sheeting on an absorbent work surface, then heating it with a hair dryer will create a smooth, wrinkle-free substrate.
  • Adhesive-coated supports prepared on polyethylene sheeting substrates are usually left on the substrate until adhesion to the artifact.
• Teflon-coated glass cloth
  • Available in a variety of gauges and sizes.
  • The most expensive casting substrate material. It is usually reused but must be cleaned carefully to prevent scratches that can affect the quality of the adhesive coating.
  • Heavier gauges lay out easily but crease permanently if bent.
  • Produces coatings with a matte finish.
  • Adhesive coatings release very easily.
  • Adhesive-coated supports prepared on Teflon-coated glass cloth substrates are usually released from the substrate and stored on silicon release paper until adhesion to the artifact.
• Polyester film (Mylar® or Melinex®)
  • Widely available in a variety of gauges and sizes.
  • Relatively inexpensive, usually considered disposable.
  • Produces coatings with a high sheen.
  • Coatings release less easily than from other substrates; some of the adhesive remains on the polyester film.
  • Adhesive-coated supports prepared on polyester film are usually left on the substrate until adhesion to the artifact. Very thin polyester film (0.0005" or 12.7 μm) can be torn from the adhesive coating in strips during the reactivation process, preventing the support adhering to the textile prematurely.
• Silicone-release polyester film (Mylar® or Melinex®)
  • Available in a variety of gauges and sizes.
  • More expensive than regular polyester film, usually considered disposable.
  • Produces coatings with a high sheen.
  • Coatings release more easily than from regular polyester film.
• Silicone-release paper
  • Available in a variety of gauges and sizes.
  • More expensive than regular polyester film, usually considered disposable.
  • Produces coatings with a high sheen.
  • Coatings release more easily than from regular polyester film.
  • Can be used only with solvent-based adhesive solutions. It buckles when used with water-based adhesives. 

Support Materials

Sheer fabrics are most often used for adhesive support treatments. They permit greater control over the amount of adhesive and thus the strength of the resulting bond. They make a composite with greater flexibility because these fabrics have fewer points of contact with the artifact. They allow more visual access to the artifact than denser fabric supports. They are lightweight but can provide adequate support.

Considerations of flexibility or drape of the support fabric are significant, but different for adhesive stabilization treatments than for non-adhesive techniques. Adhesive coating alters the flexibility of the support fabrics such that pre-coated differences may no longer be significant. The flexibility of the textile with adhered support will always be significantly less than that of the textile alone. Adhesive films, whether custom-made or purchased, are used by layering the film between the textile and a support layer (woven fabric, non-woven, etc.).

The support is usually attached to the substrate or other support prior to application of the adhesive with tape, push pins or fold back clips. The grain of the fabric must be properly aligned at this stage as change after the application of adhesive is impossible. An adhesive coating eliminates a fabric's tendency to fray; therefore, hemming is usually not necessary.

Woven support materials:

• Silk crepeline
  • Less sheer than nylon net, but more sheer than polyester Stabiltex®.
  • The thread count for silk crepeline is higher than that of both nylon net and polyester Stabiltex®. The more closely spaced threads will pick up more adhesive.
  • Because the yarns are less regular than the extruded filaments in Stabiltex® and nylon net, adhesive coatings may also be less regular.
  • Silk crepeline is easily dyed as a whole fabric or in local areas.
  • Silk crepeline generally conforms well to textiles.
  • Although silk is susceptible to light degradation, this may not be an important factor when silk crepeline is used as an adhesive support.
  • Silk is susceptible to deterioration through exposure to atmospheric oxygen. Thus silk crepeline may not be an appropriate choice if long- term stability is required.
• Polyester Tetex® (Stabiltex®)
  • Less sheer than both silk crepeline and nylon net.  
  • The thread count for Stabiltex® is higher than that of nylon net but lower than that of silk crepeline.
  • It has a very even weave structure that can permit more even adhesive coatings than silk crepeline.
  • It is available in a range of colors but is difficult to dye if other colors are desired. It can be digitally printed in patterns or solid colors.
  • It generally conforms less well to textiles than silk crepeline.
  • It is primarily chosen for long-term stability.
  • Some conservators reject Stabiltex® as being too strong for use with silk textiles as Stabiltex® filaments can cut fragile silk.

• Nylon bobbinet or heat-set net
  • Nylon net is the sheerest fabric commonly used for adhesive supports.
  • The openness of the net structure gives it a "thread count" that is lower than both silk crepeline and Tetex® (Stabiltex®). Fewer yarns pick up less adhesive giving more flexibility and lower bond strength unless the interstices are filled.
  • Nylon net is easily dyed. Heat-set net is available in many colors.
  • Nylon net can be digitally printed in patterns and solid colors.
  • Higher quality bobbinet-constructed nylon net conforms better to textiles than lower quality net or Stabiltex®.
  • Very fine bobbinet-constructed nylon net is available in 5.9 yard (5.4 m) widths, which may be ideal for large flags and banners.
  • Although nylon is susceptible to light degradation, this may not be an important factor when nylon net is used as an adhesive support.

Non-woven support materials:

• Paper
  • Occasionally used for adhesive support treatments, most often in conjunction with starch and carbohydrate adhesives following techniques developed for paper conservation.
  • More opaque than the sheer fabrics.
  • During the treatment process, papers are very malleable and conform well to textiles.
  • The combination of a textile and an adhered paper backing is usually very stiff and two-dimensional.
  • Can be colored with acrylic pigments which are then heat-set.
• Nylon gossamer (lightweight nylon Cerex ®)
  • Edges do not ravel
  • Can be very sheer
  • Smooth surface
  • Is easily dyed as a whole fabric or in local areas.
  • Can be colored with acrylic pigments which are then heat-set.
• Spun-bonded polyester (Hollytex ®)
  • Edges do not fray.
  • Can be very sheer
  • Smooth surface
  • Made in various styles and weights, resulting in varying surface qualities and flexibility.
  • Can be colored with acrylic pigments which are then heat-set.

Substrate-free adhesive films

• Adhesive films can be formed by spreading relatively concentrated adhesive solutions directly onto a substrate without a support material. (Thompson, 2001; Haldane, 2000).

Methods of Adhesive Application

The adhesive solution may be applied in one or more coats. The precise procedure depends on the adhesive solution and the method of application.

Brush application

• Wide bristle brushes are usually used but sponge brushes also work.
• The brush is dipped into the adhesive solution and then brushed lightly over the surface of the fabric.
• Following the grain of the fabric prevents distortion during brushing.
• Brush on solvent-based adhesive solutions with a single coat, minimizing stroke overlap since the adhesive dries relatively quickly.
• Brushing water-based adhesive solutions is more forgiving since the solution dries more slowly and evens out over the fabric in the meantime.
• A brush will deposit more adhesive at the beginning of a stroke than at the end.

Roller application

• Paint rollers (foam or fleece) and paint trays can be used to apply water-based adhesive in much the same way as used to apply paint.
• A roller will deposit more adhesive at the beginning of a stroke then at the end.

Spray application

• Spray techniques are usually used with solvent-based adhesive solutions.
• The distance from the sprayer to the support combined with the degree of dilution determines whether the adhesive is still liquid or partially dry when it reaches the support.
• Liquid adhesive will coat the yarn surfaces smoothly, both front and back, and conform to the weave of the fabric.
• Partially dry adhesive forms a layer of filaments or particles on the front surface of the support. This is also known as flocking.
• Either pressurized paint sprayers or aerosol sprayers (e.g. Preval®) can be used. The pressurized sprayers tend to deposit adhesive as filaments while the aerosols deposit fine particles if the adhesive solution has time to dry.
• If the adhesive will be spray applied, or if coating on both sides of the support fabric is intended, the support fabric may be prepared by stretching over a stretcher frame. Note that fabrics will sag if adhesive solutions are still very wet when applied or if the area being coated is very large.
• When applying an adhesive coating on both sides of a support fabric, the support can be stretched on a stretcher frame and placed on a sheet of polyethylene film with the support down to coat the first side. When the adhesive coating on that side has dried, the stretcher frame can be turned over so the adhesive coating can be applied to the second side. This technique essentially produces a fabric-reinforced adhesive film.

Sponge application

• Water-based adhesive solutions can be applied by tamping over the surface systematically with a sponge.

Observations and tips for application of the adhesive to the support

• Adhesive solutions applied by brush, roller or sponge typically sink to the substrate side of the support. Only the side next to the substrate can form a bond.
• One technique used to coat larger pieces of substrate by brush or roller is to divide the fabric into quarters or smaller sections with the first strokes and then to fill one section at a time. This is particularly useful if the substrate is not fully restrained.
• Adhesive solutions applied by spray coat both sides of the support if the solution is still liquid when it reaches the support. If the solution is relatively dry, the adhesive accumulates on the surface of the support closer to the sprayer.
• For textile artifacts with losses behind which the adhesive is not desired, the adhesive can be applied to the support selectively, using a template.
• The relative humidity in the room during drying affects the drying rate of water-based adhesive solutions. The higher RH, the slower the drying process, which usually results in adhesive films that have better cohesive strength at the point when the adhesive is dry to touch. Depending on the attraction between adhesive and substrate and on the amount of adhesive applied, the wrong RH may lead to such problems as the adhesive coating preferentially sticking to the casting substrate and tearing partially away from the fabric when the casting substrate is removed shortly after drying.
• Some adhesive-coated fabrics are at risk of being stretched out of shape when being removed from the glass cloth substrate.
• Some adhesive-coated fabrics develop an electrostatic charge when being removed from the substrate. This makes them attract dust and makes larger pieces difficult to handle.
• Supports with starch and carbohydrate adhesives may be adhered directly to the artifact at this stage using techniques similar to those developed for paper conservation.

Methods of Adhesive Reactivation

In most treatment techniques, a bond is formed between the adhesive and the textile by reactivating a dried adhesive coating. This reduces adhesive penetration into the textile and minimizes problems due to adhesive shrinkage on drying. A reactivating agent (usually heat or solvent, or occasionally a combination of the two) softens the adhesive coating sufficiently to permit partial embedding of the textile surface in the adhesive, creating a bond. The strength of the bond depends on the combined effects of the concentration of the reactivating agent, the time the agent is in contact with the adhesive, and the pressure applied to embed the textile surface into the adhesive. All textile components (fibers, dyes, decorative elements) must not be adversely affected by the reactivating agent.

Heat Reactivation

• Thermoplastic adhesives can be reactivated using heat as the reactivating agent. The effective temperature is determined by the nature and concentration of the adhesive.
• Heat reactivation using a heated spatula, tacking iron, and/or domestic iron is the most common method of reactivating adhesives used when treating for three dimensional artifacts.
• Whenever possible, heat is applied to the back of the coated support through a non-stick release sheet such as silicone-release paper or polyester film or Teflon-coated glass cloth.
• A padded, non-stick surface, e.g. silicone rubber under the textile artifact facilitates heat reactivation. A silicone pad can be used for uneven surfaces.
• Temperature can be measured with temperature strips or surface thermometers if the iron does not have a numbered temperature control gauge.
• Pressure is applied during heat application. The amount and time of pressure are crucial and vary by artifact.
• A reactivated area is allowed to cool, setting the bond, before continuing to the next area.
• Overlap of heat-sealing areas will create sections of higher bond strength where heat and pressure are applied twice. This should be avoided as the resulting bonds are unnecessarily strong and the risk of impregnating the textile with adhesive is high. Constant movement of the spatula or iron is sometimes used to prevent this. Even bond strength over the entire surface of the textile is, nevertheless, difficult to obtain.

Heat reactivation using a vacuum hot table

• The vacuum hot table may be used for smooth, flat, non-textured textiles.
• The adhesive-coated support may be lightly tacked to the textile artifact before the adhesive is fully reactivated with the vacuum hot table.
• The aligned coated support and textile artifact are sandwiched between thin polyester film, placed support-side down on the table's metal plate and covered with a rubber sheet or cast nylon (Dartek®.)
• Exposed areas of the adhesive are covered with a non-stick material such as silicone-release paper.
• Temperature is raised slowly to the appropriate level (usually less than that needed for a hand held iron for a particular adhesive).
• Pressure is applied for a few minutes once the reactivation temperature is reached. Then the entire apparatus is allowed to cool before removing the artifact.
• Pressures around 40 mm Hg are considered sufficient for bond formation.

Solvent Reactivation: appropriate solvents are those that can swell the adhesive coating and are safe for the artifact. Solvent may be applied as a vapor or a liquid. Additional layers of dry blotting paper or board may be used to control solvent strength and to protect the artifact from weights.

• Solvent reactivation applied through a permeable barrier.
  • The reactivation set up usually consists of the following: layers: solvent-soaked blotter paper, a solvent-permeable layer (such as Goretx® or Sympatex®) to control solvent release to the adhesive coating, the adhesive-coated support, the artifact, and polyethylene (to reduce solvent evaporation). Pressure may be applied using glass plates and/or other weights or by vacuum suction while the reactivating agent in is contact with the artifact and/or after it is removed.
• Liquid solvent reactivation applied directly
  • Liquid solvent is applied to the adhesive coating by brush or spray.
  • Too much solvent can strip the adhesive from the support.
  • A liquid solvent can also be used following heat activation to increase bond strength.

Using Adhesives in Treatment

Localized supports - tips and techniques

• Care must be taken with the size and placement of local support to minimize stresses at the edges between the supported and unsupported areas.
• Employing underlays and overlays to treat localized damaged areas in weighted silk linings resulted in the least amount of failure following intensive mounting and exhibition (Reiter et. al. 2005)
• Small areas of damage with little associated fabric loss can be stabilized by use of small pieces of adhesive-coated supports to form bridges across damaged areas. These small pieces of support can be made of any of the materials listed above as full supports. They are sometimes called "bandaids," reflecting their typical size and shape.
• Alternatively, some of the warp or weft threads can be pulled from the support fabric before the adhesive is applied to it, creating what are sometimes called "eyelashes." These supports are less visually intrusive than small supports of solid fabric or other material.
• For very damaged or fragile pieces, “bandaids” or “eyelashes” might be used before an overall adhesive support is applied.
• Adhesive-coated threads
  • Individual threads of any fiber can be coated with a thermoplastic adhesive and heat set to make tiny, nearly invisible repairs.
  • Like "bandaids" and "eyelashes" this method is best used for damaged areas without associated losses.

• Because the weak bonds used in textile conservation adhesive stabilization treatments are easily released, additional stitched stabilization may be advisable around edges, along seams, along edges/edges of tears or losses, and over weak areas.
• The adhesive coating should be removed wherever the support is exposed through losses. Alternatively, the adhesive coating may be left in place at losses and used to adhere infill(s) as compensation for loss.
• The support may be prepared with adhesive on both sides to create a three layer structure: the textile artifact, which is adhered to one side of the adhesive support, and a secondary support fabric, which is adhered to the second side of the adhesive support. This approach may be used for structural and/or aesthetic reasons.
• A lining or auxiliary support may be needed to cover adhered support and protect it from dust.
• A rigid mount that prevents flexing may help stabilize adhesive supports adhered with weak bonds.

Consolidation of fibers

Consolidation of fibers or yarns may be considered when stitched and/or adhesive treatments are not an option. This may include degraded stitching threads, embroidery yarns, cordage, or fragile surfaces and structures.

Requirements of a consolidant:

• To give strength to the deteriorated fibers without compromising their flexibility
• Not wick into the surrounding textile
• Not change the appearance of the fibers
• Be able to wet and penetrate the fibers being consolidated
• Have long-term stability
• Once fibers are penetrated the consolidating material must remain in place

Selection and testing of consolidant systems:

Solvents

• Test solvents for carrying the consolidant and any needed to remove residual adhesive so that they do not affect the original paint binder, pigments, dye, finishes, or fabric.

• Test to see if polar solvents can be added to water-based mixtures to modify evaporation or penetration.

Adhesives

• Test the necessary concentration to effectively consolidate the fibers while minimizing other undesired changes, such as sheen and color.

• Types:

- Cellulose and its derivatives: such as wheat starch paste, Klucel G, methyl cellulose

- Protein and its derivatives: such as funori, isinglass, Fibroin-EGDE

- Dispersions such as BEVA & Lascaux

- For a full list see "Adhesives Used for Textile Stabilization"

Other considerations for selecting consolidant systems can include:

• Other planned treatments for the object, such as overall, or local wet cleaning or other adhesive stabilization.

• The ability to isolate fibers for consolidation from the surrounding object.

Application methods:

Successful application of a consolidant depends upon the viscosity of the consolidant and the surface tension and permeability of the material being consolidated. The viscosity depends on the molecular weight/structure of the adhesive and the concentration and temperature of the adhesive/solvent consolidant solution.

• Brush application
• Mist consolidation

Mist consolidation is limited to adhesive solutions of low enough viscosity which can be applied via the misting apparatus, such a nebulizer or airbrush. It is a gentle application method which is suitable for particularly degraded and brittle fibers.

Further Reading

Properties of Adhesion and Adhesives

Allen, K. "Adhesion and Adhesives - Some Fundamentals." In Adhesives and Consolidants: Pre-Prints of IIC Paris Congress, 2-8 September, edited by N. Brommelle, E. Pye, P. Smith and G. Thomson, 5-12. London: IIC, 1984.

Down, Jane L. Adhesive Compendium for Conservation. Ottawa: Canadian Conservation Institute. 2015

Down, Jane. Maureen MacDonald, Jean Tetreault, and R.Scott Williams. "Adhesive Testing at the Canadian Conservation Institute: An Evaluation of Selected Poly(Vinyl Acetate) and Acrylic Adhesives." Studies in Conservation 41, no. 1 (1996): 19-44.

Down, Jane L. "The Evaluation of Selected Poly(Vinyl Acetate) and Acrylic Adhesives: A Final Research Update." Studies in Conservation  (2014): 1-22. http://dx.doi.org/10.1179/2047058414Y.0000000129.

Down, Jane L. "The Effect of Modifiers on the Stability of a Vinyl Acetate/Ethylene Copolymer Dispersion." Studies in Conservation  (2014): 1-20. http://dx.doi.org/10.1179/2047058414Y.0000000130. 

Feller, Robert L., and Myron Wilt. Evaluation of Cellulose Ethers for Conservation.  Marina del Rey, California: Getty Conservation Institute, 1990.

Horie, Velson. Materials for Conservation. London: Butterworth Heinemann, 1995.

Horie, Velson. Materials for Conservation: Organic Consolidant, Adhesives and Coatings. 2nd ed. Oxon: Routledge, 2010.

Karsten, Irene, and Jane Down. "The Effect of Adhesive Concentration, Reactivation Time, and Pressure on the Peel Strength of Heat and Solvent-Activated Lascaux 360/498 HV Bonds to Silk." In Pre-prints of the ICOM CC 14th Triennial The Hague 12-16 September 2005, edited by Isabelle Verger, 927-35. London: James & James Publishers, 2005.

Karsten, Irene, and Nancy Kerr. "The Properties and Light Stability of Silk Adhered to Sheer Silk and Polyester Support Fabrics with Poly(Vinyl Acetate) Copolymer Adhesives." Studies in Conservation 47, no. 3 (2002): 195-210.

Karsten, Irene, and Nancy Kerr. "Peel Strength of Silk and Nylon Textiles Adhered to Sheer Support Fabrics " In Symposium 2011, Adhesives and Consolidants for Conservation: Research and Applications: Proceedings CCI Symposium, 385-404. Ottawa, Canada, 2011.

Ploeger, Rebecca, Chris W. McGlinchey & E. René de la Rie. “Original and reformulated BEVA® 371: Composition and assessment as a consolidant for painted surfaces.” Studies in Conservation 60, no.4 (2015): 217-226. http://dx.doi.org/10.1179/2047058414Y.0000000132.

Pretzel, Boris. "Evaluating the use of adhesives in textile conservation  Part II: Tests and evaluation matrix." The Conservator, no. 21 (1997): 48-58.

Tímár-Balázsy, Agnes, and Dinah Eastop. Chemical Principles of Textile Conservation. Oxford: Butterworth-Heinemann, 1998.

Tinker, Zenzie. "Workshop Notes on Thermoplastic Adhesives." Conservation News, no. 48 (1992): 39-41.

Shashoua, Yvonne, and Alice Rugheimer. "An Evaluation of the Use of Cellulose Ethers in Paper Conservation at the British Museum." In Proceedings of the Fourth International Conference of the Institute of Paper Conservation, London, April 1997, edited by J. Egan, 150-59. London: IPC, 1997.

Application Techniques

Bilson, Tom. "The Conservation of a Roman Egyptian Painted Shroud Fragment." The Conservator, no. 16 (1992): 3-11.

Chen, Chuance. "Preparation of a tengujo adhesive support for use on painted silk." In Considering Costume: The Conservation, Apparel, Adornment, and Accessories, 14th North American Textile Conservation Conference Preprints, 440-451. 2023.

Cotte, Sabine "An Evaluation of the Role of Semi-Transparent Relining in the Conservation of Thangka Paintings." Studies in conservation 52, no. 1 (2007): 2-12.

Cruickshank, Pippa, Helene Delaunay, and Lynne Harrison. "Painted Textiles and Canvas Paintings: A Collaborative Approach to Lining and Mounting." The Conservator 30, (2007): 5-18.

De Stefani, Caroline, Cordelia Rogerson, and Arthur Green. "Evaluating Cross-Disciplinary Working: The Application of Textile Conservation Adhesive Techniques to Book Conservation." Journal of the Institute of Conservation 34, no. 1 (March 2011): 90-103.

Gentle, Nicola. "The Examination and Conservation of Two Indian Textiles." The Conservator, no. 17 (1993): 19-25.

Gill, Kate, and Foekje Boersma. "Solvent Reactivation of Hydroxypropyl Cellulose (Klucel G®) in Textile Conservation: Recent Developments." The Conservator 21, (1997): 12-20.

Haldane, Elizabeth-Anne. "Notes on a new method of application for Klucel G®: substrate-free adhesive films developed for use on a fragile appliqued and embroidered textile." Conservation News, no. 73 (November 2000): 64.

Haldane, Elizabeth-Anne. "Encounters with Paper Conservation: The Treatment of a Chinese Painted Silk Dress." V&A Conservation Journal, no.49 (Spring 2005), http://www.vam.ac.uk/content/journals/conservation-journal/issue-49/encounters-with-paper-conservation-the-treatment-of-a-chinese-painted-silk-dress/

Kronthal, Lisa, Judith Levinson, Carole Dignard, Esther Chao, and Jane Down. "Beva 371 and Its Use as an Adhesive for Skin and Leather Repairs: Background and a Review of Treatments." Journal of the American Institute for Conservation, (2003): 341-62. http://www.jstor.org/stable/3180075.

Lennard, Frances. "The Conservation of the United Tin Plate Workers' Society Banner." The Conservator, no. 13 (1989): 3-7.

Lennard, Frances, Nancy Pollak, Chunmei Lin, and Wan-Ping Chen. "Blue Flag with Yellow Tiger?  Flags, Authenticity and Identity." The Conservator 36, no. 1 (2013): 3-17.

Lochhead, Vivian. "Conservation of Painted Trade Union Banners." In Lining and backing: the support of paintings, paper and textiles: papers delivered at the UKIC Conference, 7-8 November 1995, 96-101. London: United Kingdom Institute for Conservation of Historic and Artistic Works, 1995.

McClean, Lynn, and Elizabeth-Anne Haldane. "Avendale for Reformation: Conservation of a 17th Century Covenanting Banner " In The Preprints of the North American Textile Conservation Conference 2003: Tales in the Textile: The Conservation of Flags and Other Symbolic Textiles, edited by J Vuori, 143-45. NATCC, 2003.

McLeod, Miriam. "Powdery Paint: The Use of Funori with an Indian Jain Painting." In Taking the rough with the smooth: Issues and solutions for decorated surfaces, edited by Alison Fairhurst, 17-25. Victoria and Albert Museum, London: ICON Textile Group, 2012.

Muir, N.T. "Conservation of Painted Flags Using Beva 371." Conservation News, no. 26 (1985): 24-25.

Peterson-Grace, Jacquelyn. “Third Time’s the Charm? Revisiting Schiaparelli’s Shattered Silks.” Lessons Learned: Textile Conservation – Then and Now, 12th North American Textile Conservation Conference Preprints, edited by Howard Sutcliffe, Joel Thompson, Hector Manuel Meneses Lozano, Esther Méthé, Denise Migdail, Amanda Holden and Elizabeth Schaeffer, 101–118. NATCC, 2019.

Pollack, Nancy R. "Moving Pictures: Adapting Painting Conservation Techniques to the Treatment of Painted Textiles." In The Preprints of the North American Textile Conservation Conference 2003: Tales in the Textile: The Conservation of Flags and Other Symbolic Textiles, edited by J Vuori, 127-34. NATCC, 2003.

Shaeffer, Elizabeth. “An “Olympe-ic” Marathon: Technical Study and Adhesive Stabilization of a Madame Olympe Ensemble.” Considering Costume: The Conservation, Apparel, Adornment, and Accessories, 14th North American Textile Conservation Conference Preprints (2023): 117-135.

Takami, Mika. "The Conservation of a Korean Painted Silk Banner, C.1800: Paint Analysis and Support Via Solvent-Reactivated Acrylic Adhesive." In ICOM CC 13th Triennial Meeting, Rio de Janeiro, 22-27 September 2002, Preprints, edited by Roy Vontobel, 747-54: London: James & James, 2002.

Thompson, Karen. "Lascaux™ - Its Use as a Substrate Free Film." Conservation News, no. 74 (2001): 45-46.

Reviews of Past Treatments

Hartog, Frances, and Zenzie Tinker. "Sticky Dresses - The Re-conservation of Three Early 19th Century Dresses." In Postprints of the 3rd Annual Adhesives Forum of the Textile Section of UKIC, edited by Jane Lewis, 12-26. London: UKIC, 1998.

Hackett, Joanne and Lynda Hillyer. “Adhesives in Textile Conservation: A Survey of 60 Years of Adhesive Use at the V&A.” In Lessons Learned: Textile Conservation – Then and Now, 12th North American Textile Conservation Conference Preprints, edited by Howard Sutcliffe, Joel Thompson, Hector Manuel Meneses Lozano, Esther Méthé, Denise Migdail, Amanda Holden and Elizabeth Schaeffer, 200-218. NATCC, 2019.

Hillyer, Lynda. "Advances in Adhesive Techniques - The Conservation of Two Coptic Tunics at the Victoria and Albert Museum." In Textile Conservation: Advances in Practice, edited by Frances Lennard and Patricia Ewer. 181-88. Oxford: Elsevier, 2010.

Hillyer, Lynda, Zenzie Tinker, and Poppy Singer. "Evaluating the Use of Adhesives in Textile Conservation. Part 1: An Overview and Survey of Current Use." The Conservator 21 (1997): 37-47.

Karsten, Irene F., and Nancy Kerr. "The Effectiveness of Adhesive Support Treatments for Flags and Banners: Condition of Treated Artefacts in Canada and the UK." In The Preprints of the North American Textile Conservation Conference 2003: Tales in the Textile: The Conservation of Flags and Other Symbolic Textiles, edited by J Vuori, 155-66. NATCC, 2003.

Kite, Marion, and Albertina Cogram. "Re-Evaluation and Retreatment. The Reconservation and Remounting of an English Court Mantua." Studies in Conservation 51 (2002): 111-22.

Lennard, Frances, and Vivian Lochhead. "United We Stand!  The Conservation of Trade Union Banners. Tales in Textiles, the Conservation of Flags and Other Symbolic Textiles." In The Preprints of the North American Textile Conservation Conference 2003: Tales in the Textile: The Conservation of Flags and Other Symbolic Textiles, edited by J Vuori, 111-18. NATCC, 2003.

Meijer, Suzan. 2014. "Bonding issues? Adhesive treatments past and present in the Rijksmuseum". In ICOM-CC 17th Triennial Conference Preprints, Melbourne, 15–19 September 2014, edited by J. Bridgeland. Paris: International Council of Museums, 2014.

Meijer, Suzan, and Marjolein Koek. “Learning from a Treatment That Did Not Go as Planned: The Use of an Adhesive Support Technique on an 1860s Dress.” In The Textile Specialty Group Postprints 27, edited by Elizabeth Shaeffer, Julia Carlson, Kira Eng-Wilmot, Anne Getts, Kathleen Kiefer and Bernice Morris, 111-123. Textile Specialty Group of the American Institute for Conservation of Historic and Artistic Works (AIC): 2017.

Reiter, Sara, Howard Sutcliffe, Ken Sutherland, and Beth Price. 2005. "Second Time's the Curse: The Shattered Silks of Schiaparelli." In The Textile Specialty Group postprints. 33rd Annual Meeting Textile Specialty Session, American Institute for Conservation. Washington, DC: AIC. 43-49.

Tinker, Zenzie. "Pragmatism with Past Adhesive Treatments." In Symposium 2011, Adhesives and Consolidants for Conservation: Research and Applications: Proceedings CCI Symposium, 503-516. Ottawa, Canada, 2011.

Thompson, Joel, and Masumi Kataoki. "From Mummies to Modern Dress: Adhesive Treatments in Textile Conservation at the Museum of Fine Arts, Boston." In Symposium 2011, Adhesives and Consolidants for Conservation: Research and Applications: Proceedings CCI Symposium, 482-502. Ottawa, Canada, 2011.

Starch Based and Modified Cellulose Adhesives: Properties and Application Techniques

Cruickshank, Pippa, and Helen Morgan. "Lining a Banana Fibre Belt: A Cool Vacuum Table Technique." SSCR Journal 4, no. 2 (1993): 10-14.

Cruickshank, Pippa, Monique Pullan, and Jenny Potter. "Recent Treatments of Painted Egyptian Shrouds: The Influence of Condition and Intended Role." The Conservator 23, no. 1 (1999): 37-48.

Daniels, Vincent. "Starch Adhesives." In Starch and Other Carbohydrate Adhesives for Use in Textile Conservation, edited by Pippa Cruickshank and Zenzie Tinker, 11-13. London: UKIC, Textile Section, 1994.

Daniels, Vincent. "The Reversibility of Starch Paste." In Lining and Backing: The Support of Paintings, Paper and Textiles. London: UKIC, 1995.

Kite, Marion, and Pauline Webber. "The Conservation of an English Embroidered Picture Using an Oriental Paper Method: A Joint Approach." The Conservator, no. 19 (1995): 29-35.

Kite, Marion, and Pauline Webber. "The Conservation of an English Embroidered Picture Using an Oriental Paper Method: A Joint Approach (1995)." In Readings in Conservation: Changing Views of Textile Conservation, edited by Mary Brooks and Dinah Eastop. 512-20. Los Angeles: The Getty Institute, 2011.

Petschek, Carla. "The Conservation of Pro-Royalist Painted Silk Panels for a Late 17th Century Folding Screen." In Paper and Textiles:  The Common Ground – Pre-prints of the SSCR Conference, Glasgow, 19-20 September 1991, edited by Fiona Butterfield, and Linda Eaton, 117-23. Edinburgh: SSCR, 1991.

Pullan, Monique. "The Conservation Treatment of a Japanese Folding Screen." In Starch and Other Carbohydrate Adhesives for Use in Textile Conservation, edited by Pippa Cruickshank and Zenzie Tinker, 28-33. London: UKIC, 1995.

Pullan, Monique, and David Singleton. "The Conservation of The Pink Lady, a Roman Egyptian Painted Linen Shroud." In Painted Textiles, Postprints of the forum held at the Museum of London, 21 April 1997, edited by Vivian Lochhead: UKIC Textile Section, 1997.

Wills, Barbara "The Preparation and Use of Two Starch Pastes." In Starch and other Carbohydrate Adhesives for use in Textile Conservation, edited by Pippa Cruickshank and Zenzie Tinker, 20-24. London: UKIC, 1995.

Animal Glues

Haupt, Margaret, Deborah Dyer, and Jim Hanlan. "An Investigation into Three Animal Glues." The Conservator 14 (1990): 10-16.

Foskett, Sarah. "An Investigation into the Properties of Isinglass." SSCR 5, no. 4 (1994): 11-14.

Petukhova, T, and S. D Bonadies. "Sturgeon Glue for Painting Consolidation in Russia." JAIC 32 (1993).

Schellmann, Nanke C. "Animal Glues: A Review of Their Key Properties Relevant to Conservation." Reviews in Conservation, no. 8 (2007): 55-66.

Soppa, Karolina, Tilly Laaser, Christoph Krekel, Margaux Genton, and Thuja Seidel. "Adhesion and penetration of sturgeon glue and gelatines with different bloom grades." In ICOM-CC 17th Triennial Conference, Preprints, Melbourne, 15–19 September 2014, edited by J. Bridgland. Paris: International Council of Museums. 2014.

Textile Consolidation

Feng, Zhao, Hu Zhiwen, Zhou Yang, Zhen Hailing, and Huang Xiaofang "Fibroin–EGDE Consolidation: A New Method for Conserving Fragile Silk Textiles." In Symposium 2011, Adhesives and Consolidants for Conservation: Research and Applications: Proceedings CCI Symposium, 428-443. Ottawa, Canada, 2011.

Hodge, Heather. "Mist Consolidation: future treatment potential for deteriorated iron-dyed yarns." Poster presented at the 2022 50th AIC Annual Meeting, L.A. https://www.culturalheritage.org/docs/default-source/publications/annualmeeting/2022-posters/13-mist-consolidation---future-treatment-of-potential-for-deteriorated-iron-dyed-yarns---hodge.pdf?sfvrsn=3aaf1720_5.

McDavid-Conway, Anya, Jakki Godfrey, Bruno P. Pouliot, and Richard Wolbers. “Hair consolidation and Treatment of an Insect Damaged Dancing Hat from Sierra Leone.” In AIC Objects Specialty Group Postprints, Volume 13, 2006, 184-194. https://resources.culturalheritage.org/wp-content/uploads/sites/8/2015/02/osg013-11.pdf

Smith, Catherine A., Rachel A. Paterson, Bronwyn J. Lowe, and Rangi Te Kanawa. “Consolidation of Black-dyed Māori Textile Artefacts: Evaluation the Efficacy of Sodium Alginate.” Studies in Conservation 63, no.3 (2018): 139-154. https://www.tandfonline.com/doi/full/10.1080/00393630.2016.1266150

Smith, Catherine A., Bronwyn J. Lowe, Jano Swart, Patricia Fuentes-Cross, Maia Mistral and Rangi Te Kanawa. “Evaluation Five Consolidants for Five Māori Textile Artefacts.” Studies in Conservation 67, no.5 (2022): 271-288. https://www.tandfonline.com/doi/abs/10.1080/00393630.2020.1857524

Stauffer, Annemarie. "A Study of the Conservation Problems of Archaeological Textiles Treated with Synthetic Consolidants (2005)." In Changing Views of Textile Conservation, edited by Mary M. Brooks and Dinah D. Eastop. 553-63. Los Angeles: Getty Conservation Institute, 2011.

Wheeler, George and Stefan Michalski. “A Brief Introduction to Consolidation Issues.” In Adhesive Compendium for Conservation. In Adhesive Compendium for Conservation, edited by Jane Down. Ottawa: Canadian Conservation Institute. 2015.

Zheng, Hailang and Yang Zhou. 2021. “Silk Fibroin Consolidation and Tracking of the Protective Effect on Ancient Saturated Silk Fabrics.” In ICOM-CC 19th Triennial Conference Preprints, Beijing. https://www.icom-cc-publications-online.org/4459/A-subtle-shift--The-care-and-use-of-Indigenous-belongings-after-the-Calls-to-Action