[rotorwrench]

It's a form of lacquer like paint. I'm not sure what chemical properties were for certain but it's a lot like airplane dope except with more plasticizer affect. For fabric covered airplanes, there were clear nitrate dope for good shrinkage and the same with aluminum powder pigment added to reduce sun penetration. There was also a Butyrate form that was a lot less flamable and could be sprayed on for final color coats having different pigments added and more plasticizer to reduce long term shrinkage. The pyroxylin has less nitrate content and is soluble in a mix of ether and alcohol. This likely kept it flexible with a less tendency to shrink over time like nitrate dope tends to do.

The last use of pyroxylin was with book cloth used as book binding covers for hard bound books. This stuff is getting harder to source though.