Q: Is there really a difference between the various clear coat finishes in electric and acoustic guitars?
A: While some might debate this point, the newer polyurethane and polyester finishes are much more stable chemically. What this means is that a guitar with a polyurethane finish will maintain its jewel-like gloss for many decades. Meanwhile, a nitrocellulose lacquer finish tends to change over the years and typically will age along with the instrument so that it normally will produce a look we strongly associate with vintage guitars. The majority of guitars produced in the 1950s and early ’60s had a nitrocellulose finish, while newer instruments got the more stable plastic-based polyurethane or polyester finishes. More recently, manufacturers have come to realize that, while it’s more difficult to apply nitrocellulose finishes (mainly because of environmental issues), guitarists will pay more for instruments that have one. That’s because “nitro” will turn a sort of light amber color over time, so that white binding for example will eventually be a rich ivory or light butterscotch color, while poly-coated guitars tend to stay the same color over many decades. Many also feel that a nitro finish has less of an effect on a guitar’s tone, though there have been no in-depth studies of this. Poly finishes cost less to apply and thus also have an economic effect on a specific guitar. Some manufacturers have begun adding a special aging toner to various finishes to give them the warm look of an instant classic.