Originally Posted by pfox14
Definitely nitro lacquer. It is hard, durable and just about every manufacturer uses it for guitars. No need for a primer, if you use a good vinyl sealer first.
Actually nitro is soft, checks, wears easily, and most manufactures have long since switched to poly finishes for the majority of their instruments.
I get my best results by using the same finish throughout the finishing process. For example, if I do a clear nitro finish, I only use clear nitro lacquer. A vinyl sealer has a tendency to expand and contract at a different rate than the nitro on top of it and can make a nitro finish start checking prematurely. If doing a color finish, I seal it with clear nitro and spray color on top of that once the finish is level.