Choosing Materials for Storage, Exhibition & Transport

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This page provides guidance on sustainable preservation and collection care activities.

Wiki Contributors: Rachael Perkins Arenstein, Mary Coughlin, Lisa Elkin, Lisa Goldberg, Jennifer K. Herrmann, Rebecca Kaczkowski, Julia Sybalsky, Margalit Schindler, Elena Torok, Joelle Wickens

Why is the Choice of Materials Important?[edit | edit source]

The materials we use to store, exhibit, and transport cultural heritage collections can have a profound impact on the preservation of these collections. Physical or working properties (rigidity, adhesive strength, cushioning capacity, color, size, machineability, etc.) may be critical in the selection of potential products that can meet the needs of a particular application. Interactions can accelerate the degradation of collection objects, or, alternatively, materials can be selected to prioritize a stable environment. Material choices also impact the financial sustainability of institutions, the health of those working with the materials, and the heritage preservation profession’s impact on the long-term survival of our planet.

What are the Factors to Consider when Choosing Materials?[edit | edit source]

The potential for positive and negative impact resulting from material choice can make the decision-making process overwhelming. These pages aim to provide tools to help heritage preservation professionals make wise, informed choices. The initial content for these pages, as well as on-going oversight, comes from AIC’s Materials Selection & Specification Working Group (MWG). The group continues to work towards developing additional resources to aid institutions of all types in making the most appropriate choice for their needs. New resources as added to these pages as they become available.

The MWG is a community of collection care, conservation, analytical science, and allied professionals united in developing guidelines and best practices for selecting, evaluating, and disseminating information about materials used in collection care. Learn more about the MWG's work and participants.

When making a material choice, these five categories must be considered if you wish to arrive at a decision that is the best choice for the situation at hand. Deciding before considering all topics is likely to lead to a choice that only works for some stakeholders.

  1. Physical Characteristics and Working Properties
  2. Financial, Logistical and Operational Accessibility
  3. Health and Safety
  4. Environmental Sustainability
  5. Chemical Stability

Physical Characteristics and Working Properties[edit | edit source]

When we begin searching for the best material to use for a specific task, we may already know what general physical characteristics we want that material to possess. These criteria can be a good starting point in making decisions. For example, we might need something that fits a specific appearance, such as a case fabric of a certain color or texture. Or, we may be looking for a material that must exhibit a particular strength, such as a board or a laminate that could be used in the construction of a platform for a large or heavy object. A material may need to have certain working properties, or even be compatible with certain tools or building features. By determining how a material might need to look or function, we can begin to make decisions and narrow selections.

Financial, Logistical & Operational Accessibility[edit | edit source]

In a perfect world, we would choose to use the highest quality material available; one that provides the maximum level of confidence concerning chemical and physical stability, environmental impact, and health and safety (see below). In our imperfect world, restrictions outside these parameters may play a dominant role in material choice.

The nature of a ‘high quality’ material often equates to high cost. Compromise and concessions will often be required and this is OK as long as decisions are well-informed and risk vs need are weighted effectively. Sometimes, we know what we want but we can’t get it. Agreements, shipping details, availability, and other mundane logistics can limit our options. Your time spent holds value as well so balance the need with what is reasonable and practical.

Finally, even when you can afford and can receive the highest quality material, operational restrictions may create hurdles or even complete barriers. Local fire restrictions may prevent the widespread use of plastics in collection spaces, security may require storage in safes or vaults that may not be constructed of materials of choice, health and safety protocols may place restrictions on movement or handling of collections further complicating decisions.

Take all of these variables into consideration when choosing your materials; they are all important and should not be diminished. Maintain a healthy dose of pragmatism and realism and know that decisions on material use aren't made in a vacuum. Be creative in how you manage these hurdles - if you think on it hard enough, there’s always a workable solution!

Health and Safety[edit | edit source]

Using materials that do not cause health and safety risks for those who use them is a primary factor in making choices. Make sure to read and evaluate all Safety Data Sheets and conduct a Job Hazard Analysis when considering use of a new material that you are unfamiliar with or one that could create risks like the generation of heat, vapors, gasses, or fumes, dusts, and other byproducts. Check to make sure that you have an appropriately outfitted space in which to work with the materials you choose; for example, exhaust fans and personal protective equipment are necessary when working with some resin mixtures and when cutting some types of solid boards.

Environmental Sustainability[edit | edit source]

The work we do and the materials we use have an impact on our natural environment. Whenever possible we select materials that reduce our negative impact. This may mean using products that can be reused and repurposed, or actually repurposing products in our work. Using lumber from a demolished exhibition wall to build parts of shipping crates is one example of repurposing. We may be able to incorporate ways to reduce our collective carbon footprint into purchasing decisions. This may mean purchasing products that are produced locally, or made from biodegradable materials, or can be 100% recycled. We may also opt not to use a product because its disposal is particularly hazardous. AIC's Sustainable Practices Wiki pages have general tips for sustainable material use and another with information on specific materials.

Sulfur from the air and from silk degradation products caused dark tarnish on silver knives. Image credit: Photograph by van Aubel van Rooijen

Chemical Stability[edit | edit source]

Materials used in storage, transport, and display can be a source of chemical compounds that are damaging to heritage objects, particularly as those materials age. These compounds include organic acids, sulfides, oxidizing and other gaseous pollutants that interact with sensitive objects in harmful ways:

  • wool contains sulfur that will cause silver to tarnish;
  • acids in wood will cause many metals to corrode and textiles to yellow.

When storage materials are in direct contact with objects, other interactions can occur. For example, plastics can release plasticizers that will stick to neighboring surfaces. These interactions can be complex and difficult to fully characterize. Nevertheless, they can be reduced or avoided altogether through the careful selection of the materials that are brought into close proximity with objects. Information about a product’s composition and materials testing results are key resources for selecting materials with the long-term stability needed for a particular application.

The MWG's Image Gallery documents deterioration or damage caused by the use of inappropriate or incompatible materials. The images and associated information are presented as a learning resource.

How do I Prioritize these Factors?[edit | edit source]

How you might prioritize the four factors above will depend on how you assess risk. This assessment depends on three additional lenses as defined by J. Tétreault.

  1. Vulnerability
  2. Threat
  3. Context
In this figure from the CCI Technical Bulletin 32 we see that damaging acetic acid emissions of some paints and sealants level off after off‐gassing for about a month. But the cellulose acetate film which starts out stable begins off‐gassing after decades as it begins to break down

Assessing Vulnerability[edit | edit source]

Some collections are more vulnerable to pollutants or degradation mechanisms. Understanding where your object sits on the vulnerability scale will help you determine how much weight object vulnerability needs to have in your decision making process. The resources below can assist you as you seek to determine object vulnerability.

The Canadian Conservation Institute’s Technical Bulletin 32 - Products Used in Preventive Conservation by Jean Tétreault provides three tables that are important in assessing vulnerability of our collections

  • Table 1: vulnerable objects and damage caused by airborne pollutants emitted from products - Use this table to determine what kind of products (e.g. wood products, foams, cleaning solutions) will off-gas pollutants (e.g. ammonia, acetic acid, hydrogen peroxide) and what collections would be most affected (e.g. metals, limestone, lead glazes)
  • Table 2: damage due to direct contact - Use this table to examine what kinds of products can cause staining, corrosion or rust in physical contact with collections
  • Table 3: physical damage by incorrect use of products - details damage that occurs to the object by incorrect use of products

The Storage at a Glance chapters in the 2019 Preventive Conservation: Collection Storage book provides useful charts highlighting which collections are vulnerable to pollutants.

Assessing Threat from Products[edit | edit source]

When you employ a multi-layered approach in storage, you can make modifications at the room level, shelf or drawer level, and object level according to your specific collection’s preservation and protection needs. If your building envelope is deficient, or your storage environment sub-optimal, can you invest in good quality cabinets? If not, move in a level, and focus in on high-quality enclosures? If you can’t afford the archival boxes that you feel might be ideal, can you use a good quality material for the layer that touches the artifacts? Using this approach allows you to weigh the importance of the four factors in a way appropriate for your needs.

Understanding to what an object is vulnerable, as well as just how vulnerable, we can then examine potential products to consider whether they have the physical properties (e.g. strength, flexibility, abrasiveness) and chemical composition that will be compatible for their intended use. That information may be available on product spec sheets, by speaking to manufacturers or distributors, and sometimes information can be gleaned from the Safety Data Sheet [insert image]. This information can also be important to examine how the material will age or perform over time. Some materials can off-gas damaging emissions at the beginning of their “lifetime” and may be safer to use after this period is over. Other materials become dangerous as they age and deteriorate.

Recycled products will be better for the environment but they are essentially at an unknown point in their “lifecycle” and therefore could age less predictably than “virgin” products. On the other hand, they could have desirable physical properties.

Assessing Context[edit | edit source]

CCI’s Technical Bulletin 32 identifies three main parameters important in determining the probability and extent of damage by materials:

  1. "Contact: the proximity between a product and an object and whether or not they touch each other
  2. Enclosure: the surface area of the emissive products in the enclosure compared to the volume within the enclosure and its airtightness
  3. Length of exposure: the length of time a product and an object occupy the same location and can interact with each other”

A product that that might cause damage if used to construct or within an airtight vitrine might not cause damage in the more open environment of a storeroom. You may be able to use a more economical or lower grade material if it is not in direct contact or will only be for short term use like transport.

Bubble wrap may be appropriate for short term transport but a more stable material like acid free tissue could be used in between the plastic wrap and the item’s surface. This stone piece was stored in bubble wrap for decades. Leaching plasticizers left residues on the surface. Courtesy of Special Collections and Archives, Reed College.

How Do I Choose What To Use?[edit | edit source]

There are many tools available to assist those making material choices. Which tool(s) you use is guided by your level of expertise, available time, and other resources. It is possible you have arrived here already knowing the kind of support you need to come to a decision. You might wish to:

A variety of possibilities within each of these choices are listed below.

Select from lists of already tested materials[edit | edit source]

Research and test materials on your own[edit | edit source]

  • Conservation & Art Materials Encyclopedia Online (CAMEO) is a searchable information resource developed by the Museum of Fine Arts, Boston. The materials database contains useful chemical, physical, visual, analytical, safety and environmental information on historic and contemporary materials used in the production and conservation of artistic, architectural, archaeological, and anthropological materials. Material entries created by the MWG are collected in CAMEO's MWG Reference Collection and include links to materials testing results when available.
  • AIC's Materials Testing wiki pages describe various ways to analyze materials for identification and evaluation, including Oddy Test, Photographic Activity Test, microchemical testing, and multispectral imaging.
  • Review literature from the manufacturer - technical data sheets often provide useful information.
  • Speak to the vendor you might purchase the material from. Vendors, particularly conservation vendors, are often willing to research questions you might have.
  • Review Safety Data Sheets
  • AIC's Sustainable Practices wiki pages provide information on sustainable conservation practices

Work directly with a collection care professional[edit | edit source]

These pages do not provide a single list of recommended products because there is not a single correct answer to the question, “What should I use?” There are materials that are more or less likely to damage collections objects. There are objects that are more or less likely to be damaged. There are materials that are more earth friendly, more human friendly, and/or more budget friendly. You have to consider all of these things in order to make the best decision for you. We hope the resources mentioned here guide you to making smarter decisions about what to use and where to use it.

Resources[edit | edit source]

Conservation & Art Materials Encyclopedia Online (CAMEO) is a searchable information resource developed by the Museum of Fine Arts, Boston. The materials database contains useful chemical, physical, visual, and analytical information on historic and contemporary materials used in the production and conservation of artistic, architectural, archaeological, and anthropological materials.

Use for: checking material properties

The Canadian Conservation Institute (CCI) has published more than 35 Technical Bulletins, free online, containing useful and relevant information for conservation practices, research, or reference, to assist heritage professionals and institutions in the care and preservation of their objects and collections.

Use for: a general understanding the issues as well as specifics on materials that have been tested

AIC's Materials Testing wiki pages describe various ways to analyze materials for identification and evaluation, including Oddy Test, Photographic Activity Test, microchemical testing, and multispectral imaging.

Use for: checking if a materials has been tested by the preservation community and if has been considered for temporary or long-term use

The MEMORI project created a dosimeter and provides information on a practical and reliable way of determining the long-term average air quality risk to heritage objects indoors.

Use for: information on air quality and mitigation for cultural heritage collections

The IRUG Spectral Database is an ongoing compilation of IR and Raman reference spectra of artists' and cultural heritage materials contributed by individuals and institutions in the international cultural heritage community and academia, which currently contains over 2,128 peer-reviewed spectra. Material types represented are carbohydrates, minerals/inorganic pigments, mixtures, natural resins, oils/fats, organic dyes/pigments, proteinaceous materials, synthetic resins, unclassified materials, and waxes.

Use for: identifying unknowns

Preparation, Art handling, Collections Care Information Network (PACCIN)’s Material page is a compendium of materials commonly used to wrap, pack and protect art and artifacts. Each material entry has a detailed article providing information on how the materials can be used and how they react, both positive and negatively. PACCIN's forum is a searchable forum to view and participate in discussions on materials used for packing for moving and storing artwork.

Use for: getting a sense of how cultural heritage professionals feel about the use of something and any changes in observations or accepted material use.

British Museum Oddy testing report site contains the link to the published database of material test results, including Oddy and pH tests to help with decisions on determining if materials are safe to use with objects inside showcases, packing crates or storage areas.

Use for: Good for checking if something has been tested and if it passed/failed.

Storage Techniques for Art, Science and History Collections (STASHc) details storage solutions for a wide variety of collection types.

Use for: information on common materials found in conservation, with a cross reference of brand names, manufacturers, and suppliers.

The U.S. Library of Congress shares useful information on preservation, conservation, preservation science including specifications, digital preservation, collections care, and emergency management. Also noteworthy research projects are described.

Bibliographic References[edit | edit source]

The Materials Selection and Specification Working Group (MWG) has created an annotated bibliography on the Zotero platform to collect resources focused on choosing materials for storage, exhibition, and transport, for the benefit of collecting institutions and cultural heritage communities. The library can be found at here, and any questions or comments can be addressed to the Zotero administrators via email.

AIC Resources[edit | edit source]

Institutional Resources[edit | edit source]

Standards & Specifications Organizations[edit | edit source]

Resources for Paper, Photographic and Film Collections[edit | edit source] Searchable website for guidance and fact sheets relating to preservation, conservation, digitization, emergency planning, fundraising, and surveys for different types of collections (paper, photographs, objects, textiles, audiovisual, etc). Collection of research and ideas from many individuals and institutions, about iron gall ink and ink corrosion serving as a valuable resource of knowledge and knowledge sharing. The website provides information, skills, and tools needed to care for digitally printed collections. It is designed with a curriculum-like structure giving description of major digital printing technologies, identification methods for various digital print types, descriptions of deterioration characteristics for different digital print materials, and research into stability best preservation for digitally printed materials. Includes a glossary of terms. is a resource for best practices in film preservation, providing guidelines the preservation of all types and formats of film materials. It addresses the requirements for preserving black-and-white and color film and nitrate, acetate, and polyester-based film, as well as specific issues for motion-picture film, sheet film, still roll film, microfilm, and aerial film, including the management of collections containing a variety of media types. The focus is primarily on storage, condition surveys, and the development and implementation of best-fit environment-based strategies.

The Graphics Atlas presents an object-based approach for the identification and characterization of prints and photographs. The visual comparison tool is very useful. This website is designed to show the variations and similarities in 283 digital prints made with different processes, different materials (colorants, inks, toners, paper types, film, brands), and at different times. The use of the same image (the enlarged area of a human eye at approximately 30x magnification) allows the characteristic qualities of different process-material-printer combinations to be examined and compared to each other.

Additional Resources for Research[edit | edit source]

Journal of the American Institute for Conservation homepage, with links to how to access the journal. Read JAIC open access articles on CoOL
Great for open access electronic publication for scientific research for the preservation of cultural heritage!

Conservation Online (CoOL) promotes collaboration and is a helpful freely accessible authoritative and trusted platform to generate and disseminate resources for colleagues working to preserve cultural heritage worldwide. Jump to CoOL's search page.
Use for: getting a sense of how cultural heritage professionals feel about the use of something and any changes in observations or accepted material use. PACCIN’s Material page is a compendium of materials commonly used to wrap, pack and protect art and artifacts. Each material entry has a detailed article providing information on how the materials can be used and how they react, both positive and negatively. Good for getting a sense of how cultural heritage professionals feel about the use of something and any changes in observations or accepted material use. The website of Library and Archives Canada (LAC) includes publications, archival records, sound and audio-visual materials, photographs, artworks, and electronic documents. Related page: Online publication of conservation related research

Health, Safety, Indoor Air Quality and Sustainability Resources[edit | edit source] Information on third party product testing from an industry perspective for indoor air quality, low chemical emissions, sustainability, recyclability, and other certifications useful for choosing products during renovations, building, painting, cleaning, etc. Conservation information can be gleaned from understanding the different certifications (especially low chemical emissions), when combined with composition knowledge.
Good for searching for low VOC products.

GREENGUARD product certified search site: Information on indoor air quality as influenced by carpets, cushions, and adhesives used in homes and businesses. CRI launched its Green Label program to test carpet, cushions and adhesives to help specifiers identify products with very low emissions of Volatile Organic Compounds (VOCs).
Good for searching for low VOC carpet, adhesive, cushion products.

CRI product certified search site: Information on life-cycle-based, multi-attribute standards and certification of products and services that can prove they meet strict criteria for human health, reduced environmental impact and excellent performance. Operating as a nonprofit since its founding in 1989, Green Seal has certified thousands of products and services in over 450 categories, and is specified by countless schools, government agencies, businesses and institutions. Good for searching for low VOC products. Greenseal product certified search site: Information on products guaranteed to meet high standards for indoor environmental quality and/or resource conservation. Focused on making it easy for school personnel and design professionals to select, specify, and document building materials that meet strict criteria; CHPS Pre-Approved Products have been reviewed and certified by CHPS to meet the requirements for Low Emitting Materials*, Recycled Content, Certified Wood, Environmental Product Declaration (EPDs) and/or Product Health Information Reporting (e.g. HPDs).
Good for searching for low VOC products.

CHPS new listing of low emitting, recycled content, certified wood, or rapidly renewable products are contained in the CHPS Pre-Approved Product page at Use the Sustainable Minds Transparency Catalog to identify products that meet our requirements for product transparency declarations (EPDs or HPDs). ( Website describing green building, the practice of designing, constructing and operating buildings to maximize occupant health and productivity, use fewer resources, reduce waste and negative environmental impacts, and decrease life cycle costs. Good for understanding LEED definitions. Low emitting materials credit information:

The goal of the NIBS–IEQ Products & Materials Committee was to develop procedures and guidelines to aid people in making informed material selections in order to construct a building that will be accessible to persons with multiple chemical sensitivities (MCS) and/or electromagnetic sensitivities (EMS). Large amount of information on indoor air quality, as related to health, environmental, and building issues. European website - Eurofins "Indoor Air Comfort" (IAC) – with information about product certification tool to show compliance of a product with low VOC emissions criteria. There are two levels:

  • Standard level "Indoor Air Comfort - certified product" shows compliance of product emissions with the criteria of all legal specifications issued by authorities in the European Union and its Member States.
  • Higher level "Indoor Air Comfort GOLD - certified product" shows additional compliance of product emissions with the criteria of many of the voluntary specifications issued by most relevant ecolabels and similar specifications in the EU.