Originally all electric guitars in the 50's and 60's were made with a Nitrocellulose lacquer finish. Polyurethane and Polyester only came into commercial use in the late 1960's and since then most guitar makers have switched to Poly as it is more durable, higher gloss and less toxic.
Yet despite the advantages of Poly, Gibson continue to only use Nitro as the finish on all their USA made electric guitars including the iconic Les Pauls, SGs and 335 / 339s. Given strict EPA controls in the USA, steadfastly sticking to Nitro must pose some significant challenges for the Gibson factories.
Fender mainly use Poly with a few exceptions such as the Original Series which are built to authentic specs of the early 50's and 60's Fender models. We have it on good authority that Fender ship these guitars to Mexico to have the nitro finish applied, due to the strict EPA controls in the USA. So how, and perhaps more importantly why, does Gibson stick with Nitro?
Has a softer and slightly "wetter" feel
Some say it allows the wood to expand and contract more naturally, making the guitar more resonant
Over time will begin to lightly crack and develop classic vintage checking
A brand new nitro guitar smells amazing when you open the guitar case (but don't inhale the fumes too much!)
Popular with lovers of guitars that have truly authentic vintage guitar looks
Considered glossier and more durable
More colourfast and doesn't check as easily
Synthetic resin leaves almost no solvents during curing
More resistant to cracks, scratches and chips
Easier to apply in the event of repairs etc.
So, the jury's decision?
Nitro isn't everyone's cup of tea, but for many it looks great, lets the guitar "breath" and ages into a classic instrument.
On the other hand, modern Poly finishes applied with the latest technology are thinner and better than ever before, and pose no health or environmental risks.
At the end of the day, the finish is only one of many factors that contribute to each guitars unique tone, feel and looks - but it may be an important consideration in finding the guitar that’s right for you!