Re: Guitar finishes and tone/looks
Low end guitars (Squiers, lower RG series Ibanez, etc) have a polyester finish IIRC. It's basically like Chip said, a 1/8" layer of plastic over the wood. Very durable stuff. If took me a couple days with 80 grit on a palm sander to take all the finish off my Ibanez.
I can't tell a tonal difference between different finishes. I think the biggest difference would be in the amount of finish applied rather the the type of finish.
I'm going with a polyurethane clear coat on my Ibanez. The first time I tried to laquer the headstock the finish seemed too soft. Even after several weeks I could make indentations in the finish. Plus, I really like the way that polyurethane yellows.