That's a new one on me even though from the time I was about 8 until I was 17 or so, I spent several hundred hours a year with my nose in a Herter's catalog...
I found this:
"Herter's used to sell paints, for painting fishing lures and duck decoys, that used nitrocellulose dissolved in ketone as a polymer base. "Celluloid Enamel" I used to have a collection of colors of those paints."
here: http://www.longrangehunting.com/forums/f28/powder-ring-barrel-128890/index2.html
Makes as much sense as anything else, I guess..