Fillers are required to level the wood by filling the wood pores. Paste fillers and diluted paste filler using solvents can be used to level open grained and closed grained surfaces, respectively. Sealers and transparent films are either shellacs, varnishes, or lacquers. Shellac is a natural resin which is combined with a solvent such as alcohol. Varnished are slow drying coatings which are generally polyurethane.
Solvents found in varnishes include turpentine, varnalene, and xylol.
Solvents used in lacquers include acetone and ethyl alcohol. Thinners used in lacquers including toluene, benzene and xylene. This is done by limiting the emission of hazardous and toxic chemicals into the air. Permits are also required for any equipment or process that emits or controls air contaminants unless specifically exempted. Permits for new or modified facilities must be obtained before any construction begins.