Found an interesting PDF file out there put out by a company called Cementex.  I think maybe that Holden Latex is now the name of the company or the bought them out. The PDF below even mentions puppets!
http://holdenslatex.com/pdf/l200masks.pdf

Once you check it out you might want to browse some of the other documents they have. http://holdenslatex.com/learningcenter.aspx

Thought I would add that the L-200 mentioned in the article is now called HX-200 on their site. http://holdenslatex.com/l-200castinglatex.aspx  I've always heard it called L-200 so this may be a recent change.

Good Information Shawn..............and a great find.

Hey! that "Halloween Adventure" sign on the first page of the pdf is in NYC right around where i used to live, unless i'm mistaken.