Well, it looks like silicone molds will work out great with the casting plastic I’m playing with these days.  Unfortunately, silicone isn’t cheap, and it takes a ton of it to make a sword mold.  I made the smaller Ryo katana for now (the masquerade version).  I think it’s time to get back to the vacuu-form table, that should let me make cheap molds quickly, at least compared with silicone casting.  Just need to wait for the plastic sheets I ordered to arrive… and work with the silicone I have for now, of course.