Vegetable glycerin, Zeus
Glycerine is a useful solvent, because it dissolves most of the water-soluble substances and even metal oxides. Glycerin can also be used as a lubricant and as a fabric softener for fabrics, leather and parchment. Glycerin is used to make the color drier on the palette slower. It is useful, but should be used in small quantities because otherwise it will darken the colors. Only egg white gouache is not affected by glycerine. A little glycerine can be added to the primers to make them more flexible. The glycerin mixed with water (with which it combines perfectly) can be used to soften the canvases made rigid by the inappropriate application of glues. The glycerin mixed with alcohol (in a ratio of 1: 1), can be penetrated into the pictorial film to make the layers of color stiffened by time more flexible
