Yesterday evening I decided to make good on my promise to learn a little more systematically about egg tempera techniques. There is an excellent website for this purpose, called temperaworkshop.com, and I was browsing through it. I was amused and surprised to discover, reading about the gesso foundation upon which this medium is painted, that it is actually made from calcium carbonate. Not familiar to you? Well, it is to me. This is the same substance with which climbers dust their hands in order to improve adhesion on the rock. Fancy that!
Almost the biggest difference to which I’m having to adjust in taking up tempera as a medium is the slowness of development. The surface is built up by a succession of layers of small strokes, permitting the under-layers to show through the upper ones. There are no big, bold washes of colour. For half the time I’m working with brushes smaller than a number 3, and quite a lot of the time with a 0. The problem is that, because of the transparency of these layers it is very difficult to conceal mistakes. The positive side of this, however, is that it is easily possible to scrape off rubbish and start again. I’ve done that once already, sanding back to the gesso surface.
PS: If there is anybody else out there with experience of attempting egg tempera I would be interested to exchange notes with you.