What differences are there between Epiphones and Gibsons?

The most notable difference between Gibsons and Epiphones is in the finishing process. Gibson uses nitrocellulose lacquer, which tends to be fairly expensive to apply; it has to be sprayed, buffed out, sprayed again, etc., which is *very* time consuming, and adds quite a bit to the cost.

The advantages are that a nitrocellulose finish has a very attractive lustre, and that as it ages, it hardens and gives what's referred to as "vintage tone"; the drawbacks are that it tends to be fairly fragile, along with the difficulty in applying it. Epiphone, on the other hand, uses polyurethane, which is quite a bit less difficult to apply, and takes fewer coats to produce a good finish; most companies that produce low-to-medium-end guitars use poly.

Polyurethane is a *very* hard and durable finish, which is its other big advantage; the drawbacks are that a high-gloss poly finish can look like the guitar has been "dipped in plastic", and poly doesn't "breathe" the way that nitrocellulose does. Other than that, Gibson uses higher-quality materials and hardware, and builds their guitars in the USA. (text from Heliman)