Can the face painting cause mess in my house/venue?

Not really. Face paint dries on the skin in a matter of seconds or a few minutes at the most, and once the child leaves our chair the paint is usually already almost fully dry. Even if some paint got on a surface, it is water soluble ie. wipes off easily with a wet cloth. However, in the very unlikely event that a color prone to staining (such as blue or green) somehow got on a rug or other fabric surface, staining is possible. If you are very worried about stains on your chairs or carpet, you could cover them with something or remove the rug.