ORIGINAL: Michaelj2k
Non taughtening nitrate and butyrate dopes have been plasticized by the manufacturer. I use them on silk covering and nary a warp develops. Use the appropriate thinners for each, clean your brushes and spray gun with acetone or mek.
I agree. The finish on my Pitts M12 (my avatar) is butyrate dope over nitrate over dacron glider fabric. It's still as bright and flexible as when it first flew over five years ago with no signs of cracking or aging. I just finished a minor repair to one wingtip that I accidently bashed into the shop door and the repair is almost invisible with the new colors matching the old perfectly. Modern butyrate needs nothing more than thinner, retarder, and patience.
Curt