Wood putty, also called plastic wood, is a substance used to fill imperfections, such as nail holes, in wood prior to finishing. It is often composed of chalk combined with a binder that dries, sometimes with a diluent (thinner), wood dust or pigment. Pore fillers used for large flat surfaces such as floors or table tops generally contain silica.
Putties are usually sanded after they dry before applying the finish.

Many different brands, types, and colours are commercially available. Binders include lacquer, water-base, and linseed oil. Some woodworkers make their own putty using fine sanding dust (not sawdust, which is too coarse) with wood glue or a wood finish such as shellac.