Here are the 3 little test scrolls side by side. The one on the left has the loose pigments with Gum Arabic as binder. The one in the middle has glare (prepared egg white) as binder. The one on the right has egg yolk as binder. You can see a difference in the color and even texture of the pigments in all 3 preparations. (Vellum has a slight curl from being on the animal.)

I think I’m going to use the glare on the big scroll.