Have you ever read one of our articles, and wondered, “what does that mean?” The first installment in a new series, we’ll be highlighting different conservation terms to support education. Happy learning!
Acid Burn
Acid burn is yellow or brown staining on paper. Sometimes referred to as mat burn, acid burn occurs when an artwork is framed with paper materials that are not acid-free. Acidic materials cause more than cosmetic damage; acid burn can cause deterioration and damage such as embrittlement, discoloration, and fading.
Cleavage
Cleavage describes the separation between two previously bonded layers of a structure such as an inlayer veneer separating from its support, or the paint layer peeling from the canvas or panel surface.
Foxing
Foxing is the term the describes small yellow brown spots or blotches on paper, but is not the same as mold stains. Foxing is the result of metal contaminants in paper that has been exposed to high humidity causing the metal to oxidize and rust.
Gold Leaf
Traditionally, gold was beaten by hand but today it is beaten by machine producing a thinner leaf. It is cut into 3 3/8” squares and sold in books of 25 leaves. Leaf can not be touched by hand or it will disintegrate. The leaf is transferred to an object with a brush called a gilders tip. The nature of the finish the gold leaf produces depends entirely on the surface upon which it is placed. Finishes range from matte oil gilding surfaces to brilliant, burnished clay surfaces with water-gilding. The advantages of a gold leaf finish, as opposed to other gold colored finish, are its reflective quality (the beaten leaf has more reflective quality than anything produced with pigment), its durability (properly gild surfaces can last for centuries) and its stability (it does not tarnish).
Varnish
Varnish is an applied surface film, usually of a transparent, cloudless resin. It imparts an even gloss to the surface and providing protection to the paint layer. It also saturates the pigments creating a more vibrant surface, seen in this image, mid-application. You can learn more about varnish in our archives, “Thoughts on Varnish from a Conservator.”
