Making gouache or egg tempera from pastels
I was thinking of using soft pastels to make either gouache or egg tempera. Can anyone think of any reason why the ingredients in soft pastels would not be compatible with either a gouache medium or an egg tempera medium? I am aware that different pastel manufacturers may use different binders such as gum tragacanth, gum arabic, and methyl cellulose, and might have other ingredients.
This is not taking into consideration the expense, time, safety, storage issues, etc. Before I start on this project, I at least want to make sure I am using artist quality materials.