Hello,I believe I may have benefitted my future layout with a Hex grid Silicone Pattern to cast Hex Brick sheets in various mediums..I saw this today at Wally World, & bought one, cuz it said Silicone, & was the right size!!!It is about 6" across the flats & it could let me make many groutable casts.Take a look;
http://www.walmart.com/ip/Gourmet-Club-Silicone-Pot-Holder-and-Trivet/22374192
Just Sharing!!!