Eastman stops using Nitro switches to Truetone

[TomC]

Interesting timing of this thread. I had just read the older post from Luthier Talk about the differences between nitro and poly referenced above. I found one point the author made about the original use of poly to be interesting:

"as a general rule, Nitro has a build of 30% solids.. that's the stuff we see as the shiny finish when its all done.. and approximately 70% solvents that's the toxic stuff that evaporates into the air around us.... Polys on the other hand are almost the reserve of that.. with nearly a 70% solid build and 30% solvents.. so you can see easily how the thick finishes associated with the early polys came about."

So if finishers were originally applying the poly at the same rate as nitro you could end up with a thick heavy top finish after solvent evaporation. More than likely most manufacturers who use poly have improved their processes to account for the lower evaporation - Taylor for example. Furch has also "perfected" the finish material with a proprietary UV hardened lacquer. https://www.youtube.com/watch?v=7EpCWoKfuFA Probably a little bit of marketing in there. 

IMHO - the proof will be in the finished product.