How the Electric Guitar is Made
Coating gives the guitar a smooth finish

The first step is to bring out the wood grain

Coating is performed in several steps: undercoat, intermediate coat, coloration, and then a topcoat.
The guitar in the photo has not been coated yet. Although the luthier will next apply an undercoat, as he does so he will wipe a grain filler into the surface to give it its initial color. He coats the instrument with an organic solvent in which the paint has been dissolved, to help bring out the woodgrain.

The woodgrain is brought out instantly

The woodgrain is brought out instantly

Solvent used for the grain filler

Solvent used for the grain filler

The surface is polished to a mirror sheen

Next, a spray gun is used to apply the undercoat. The goal here is to even out any subtle unevenness in the surface of the wood. Guitars used to be sprayed with nitrocellulose, but now polyurethane or some other resin is used. The sound ultimately produced from the guitar will vary based on the type of paint and how it is applied.
The luthier sprays paint, dries it, polishes it with paper, and then repeats this process several times until the surface has a beautiful mirror sheen to it.

A spray gun is used to apply the undercoat

A spray gun is used to apply the undercoat