Wood fillers have two jobs. The first is to fill holes such as dents, nail holes and cracks. The second job is to fill the pores of open-grained woods so that a stain can be applied evenly. Thicker fillers are for filling holes and don’t work well as grain fillers. Grain fillers are thinner, like batter. There are a few fillers that can do both jobs if thinned down to fill grain pores. For filling holes, many woodworkers use a filler made of nitrocellulose lacquer band and fine wood particles called wood flour.
