Body filler, often referred to as car bog or car putty, is a thick, paste-like compound used to repair dents, holes, and imperfections in vehicle panels. It’s typically applied after surface preparation, then sanded smooth once hardened to create a seamless repair ready for priming and painting. Made from polyester resin and a hardener, body filler is essential in automotive repair for restoring the original shape and surface of damaged panels. See our guide on how to apply body filler.