As far as I can tell, without paying money you can only get two permanent masks. You get the one random legendary mask(which you can break down to upgrade a different one) and the one paper glue from the free package. Not sure if everyone gets it from free package but seems that way so far. The only packages listed as having a possibility of glue are the pay ones.

It's a rare drop from the normal bags I think, but I got one from the free treasure box you get at the start.