Products bearing the AP seal of the Art & Creative Materials Institute, Inc. (ACMI) are certified non-toxic. A product can be certified non-toxic only if it contains no materials in sufficient quantities to be toxic or injurious to humans, or to cause acute or chronic health problems.
Pasto is a thickening gel that increases the body of the paint, giving pleasing textural lines and adding extra gloss. It is best suited for use with tube watercolor. Mix it with the paint or use it pure by applying it in several layers with a spatula on the surface of the paper prior to painting. Pasto dries slowly, reduces the flow of color, and remains water soluble.