Film formers are a large group of ingredients that are typically found in hair-care products, but that are also widely used in skin-care products, particularly moisturizers and face masks.

Standard film formers include pectin, hydroxypropyl methylcellulose (HPMC), hydroxypropyl cellulose (HPC), carboxymethyl cellulose (CMC), pullulan, polyvinyl alcohol (PVA), polyvinlypyrrolidone (PVP), chitosan, microcrystalline chitosan, quaternized chitosan, polyvinyl pyrrolidone, vinyl pyrrolidone/vinyl acetate copolymers, polymers of the acrylic acid series, acrylates, acrylamides, quaternary cellulose derivatives, collagen, hyaluronic acid and salts thereof, gelatin and similar compounds.

When applied they leave an imperceptible film over the skin. It’s a pliable, cohesive, and continuous covering over the hair or skin. This film has water-binding properties and leaves a smooth feel on skin, as well as gives the skin an appearance of being firmer. Film formers last until you wash them off and reapply the product. Film-forming agents can be weak skin sensitizers for some people.

Polyvinyl alcohol/PVA alcohol is the functional ingredient in peel-off masks and “rubber” masks.

Sources
Contact Dermatitis, October 2007, pages 242–247