glair

In medieval painting glair was sometimes used as a binding media for pigment. I used the translation of the ”recommended” recipe from "an anonymous eleventh-century tract in Berne, called De clarea..." (Thompson 50).
Read on to see how I made some glair with a medieval recipe and modern equipment:

There are two kinds of glair, one of which is made by beating and the other by pressing.  The one made by pressing is considerably more brittle or weak than the beaten kind, and is, moreover, contaminated; since, being repeatedly squeezed or filtered through wool or cloth, it picks up dirt from the hand of the person who presses it...
both color and glair, therefore, should always be handled very cleanly; for there is no other way to make things beautiful than by being choice and careful about materials.

Not wanting to contaminate it with hand oils, sweat and dirt and being unwilling to make a medieval whip and tire myself out, I chose to use a modern mixer to whip the egg white rather than a sponge to foam it.

An egg white from a free range chicken (d'Avignon) was whipped until stiff peaks formed. The bowl was covered and I let it sit for fifteen hours at room temperature (low 60Fs). I poured the resulting liquid off through a sieve into my jar. (Turner) My readings suggest that glair is easier to work with once it sits for some time.  After a month or two this clearly will be rotten egg so I plan to try it only in a well ventilated area.