I am working on some definitions; the definiton I am working on right now is glair.
My first step is reference books and then I go to primary sources whenever possible. My resources, older reference books, state that glair is used for bookbinding, gilding, and painting watercolors on parchment. I talked with one bookbinder and he gave me his recipe for preparing glair and said it was used most for tooling and gilding simultaneously. He said that he used a “bone folder” (non-metal) for folding vinegar and skim milk into frothy egg whites that had set. However when I tried to verify with other book binders no one had heard of it. Is my first source reliable? Is the term bone folder in common use?
I also contacted artists working on parchment. Only one had heard of glair and she didn’t know if it was still in use. She later said that one of her colleagues uses glair with dry pigments when painting and gilding on parchment but she didn’t know if he made his own glair or bought the commercial variety. Does anyone know the pros and cons of handmade glair vs. commercial glair?
Thank you in advance for your help.
Susan
That basic formula does appear in historical texts, at least essentially those ingredients. There are several recipes listed here: https://books.google.com/books?id=MQohAQAAMAAJ
and additional recipes here: https://archive.org/details/FormulasForBookbinders/page/n13
My “painting techniques” instructor, a knowledgeable tempera painter, warned against experimenting with glair, due to concerns that the resulting paint might be brittle and detach. I don’t have any hands-on experience with this material in gilding or binding.
A bone folder is a common tool in bookbinding and fine stationery, useful where clay coatings and painted surfaces might pick up indelible marks from metal tools. (Literally for folding and creasing signatures of paper, envelope flaps and folded cards. ) In this case, it’s probably used because it’s less reactive with acids. Unless I’m missing something, I think a glass or plastic tool would be just as good.
Thanks Matthew, I was teaching all day and am only now able to comment. The term usually refers to a binder extracted from egg white. The white is beaten to a froth and allowed to sit for a while the liquid that exudes from this is collected and called glair. Glair was more commonly used as a binder for illumination on parchment. It was also as an additional binder in water gilding where it supplemented the glue already in the ground and bole. It is a weaker binder than egg yolk and is probably best avoided outside of the above. As a side issue, some painters used glair as a temporary varnish applied before the work could receive a more permanent varnish. Very often this layer was not removed and it can be seen as a grayish turbid and generally insoluble coating. In short, this is not advised.