Kwally89's effort looks like the best so far, I should know, I'm working on one myself. I've been researching leuco dyes and thermochromatic paints and found a few that look like they'd work.
One industry sales rep actually asked me why so many people are writing him asking about this in the last few days. ( Probably a bunch of fellow prop-building fans like us. ) When I told him, he thought it was a pretty cool idea but was partially upset that so many people wouldn't tell him what was going on. ( A lot of people with $$ signs in their eyes and hopes of selling masks on eBay for $780 each, perhaps? ) The sales rep was also partially relieved that at least I was willing to level with him and say WHY I wanted the dye. In fact he was so appreciative that someone finally leveled with him he started telling me all sorts of dyes and paints that he didn't bother to tell anyone else.
Based on this I have a good deal of confidence that I can make my own moving mask but Kwally89's effort has the PERFECT dual pattern layout and appears to be getting done via silkscreening if I'm not mistaken. ( Mine would only be hand painted. Yuck. ) Not to over-hype it, but Kwally's really got the best deal going. Considering as how I was willing to toss $300+ into this, his price for a mask can't be passed up on.
