Powders are sometimes the messiest of the color cosmetic products that formulators have to work with. They are dry particulates that are designed to cover the skin with color and effect as well as have functionality such as oil control or anti-aging properties. Formulation is not very difficult and the ingredients used will be based on whether the final product is of the loose or pressed variety.
Loose powders, of which we see many new ones on the market in the form of mineral foundations, are either talc-free (utilizing various grades of mica and sericite) and contain mostly small particle size powder ingredients. They just need to be ground and filled into suitable containers. Pressed powders use larger particle size talc for pressability and maximum opacity and contain a liquid (or sometimes a wax) binders to help compress the powder for filling into pans. The binder is the all-important ingredient in the product that coats all the particles in the powder allowing them to compress to form a cake when pressed into a pan.