is a planar distortion of paper, parchment or textile. It appears as wrinkles, puckers or ripples, often in parallel ridges, without creases.
wrinkling; puckering; rippling;
Synonyms in English
The mid-1800s saw an increase in machine made paper. This new process caused the fibers to align in a parallel manner, creating a grain which decreased fiber bonding and stability. (van der Reyden 1995)
The fibers in paper and parchment react to fluctuations in temperature and humidity. Moisture, whether in vapor or liquid form, causes fibers to expand. Conversely, fibers can release water into a dry atmosphere causing media to shrink. Either situation can result in cockling. Preventative conservation should aim to maintain a relative humidity level between 40-50 percent. (Long 2000)
Severe cockling may cause aesthetic and structural problems. Care needs to be taken that the cockled areas of an image are not abraded.
Planar distortion of paper and parchment can usually be reduced or eliminated by first expanding the fibers with controlled humidification, then gently allowing the media to 'stretch-dry' between blotters under weights. (Wasner 2001)
In cases where the media is too sensitive for this type of procedure, a more deeply cut mat window can be made to protect the surface. (Morris n.d.)
With textiles, cockling can occur as a result of uneven tension between fibers during weaving, or variations in the types of fibers used. (MFA 2013) These cockled areas can be treated with damp blotting paper, a warm iron, and then weighted to reduce distortion. (Lennard & Ewer 2010)
AIC. BP Chapter 5-Written Documentation. "Glossary of Terms". Accessed 13 April 2014. Retrieved from http://www.conservation-wiki.com/wiki/BP_Chapter_5_-_Written_Documentation#5.6_Glossary_of_Terms.
Cleveland Conservation of Art on Paper. “Planar Distortions.” Accessed March 21, 2013. Retrieved from http://www.conservationofpaper.com/planar.html.
Getty Research Institute. Art and Architecture Thesaurus online. "Cockling." Last modified 2004. Retrieved from http://www.getty.edu/vow/AATFullDisplay?find=cockling&logic=AND¬e=&english=N&prev_page=1&subjectid=300228335.
Lennard, Francis and Ewe, Patricia, eds. Textile Conservation: Advances in Practice. London: Routledge, 2010.
Long, Richard, W. Caring for Your Family Treasures. New York: Harry N. Abrams, Inc., 2000.
Morris, Patricia. The Collectors Guide. Conserving Works on Paper. Last modified September 24, 2007. Retrieved from http://www.collectorsguide.com/fa/fa010.shtml.
Museum of Fine Arts Boston. CAMEO. "Cockling." Last modified July 24, 2013. Retrieved from http://cameo.mfa.org/wiki/Cockling.
Schell, Laura. "Cockling." 2009. Retrieved from http://www.paperconservationwny.com/treatments.htm.
The Fine Arts Conservatory. "Glossary." Last modified 2006. Retrieved from http://www.art-conservation.org/GLOSS_Paint.htm.
van der Reyden. Storage of Natural History Collections: A Preventative Conservation Approach. vol. 1. "Paper Documents." (available from) Society for Preservation of Natural History Collections, 1995.
Wasner, Heather. Library of Congress. Conservation Corner. volume 60, number 4. "Preserving Lafayette's 1824 Maps." April 2001. Retrieved from http://www.loc.gov/loc/lcib/0104/preserving_lafayette_maps.html.