This is how I've been making my pop mold frames. I figure out the lenght and with of the mold needed according to the lenght and with of my master and the number of cavities that I want it to have, I then take 3/4 x 3/4 inch pieces of wood, I use pine, and cut 8 pieces when making a 2 part mold. For example lenght = 4 pieces 8" long and width = 4 pieces 6.5" long to make to mold halves frame. This will make a mold 8"x 5" or 6.5"x 6.5" if my math is correct. lol I use drywall screws to assemble the pieces. On the bottom halve of the frame i attach a piece of 1/4" plywood or plexy glass cut to the correct lenght and width of the mold frame, attach with screws. 3/4" is the reccomended thickness of pop molds so this guides me to the correct thickness to pour. I put vaseline on the frame and bottom then pour the pop to the top of the 3/4" frame, submerge my master and 2 marbles in to the hale way point, let that cure some, lube up the top of that half including the marbles this time, put some foil around the edges if you like but won't be needed if you used the vaseline liberally. Then take the top frame that should already be assembled with the drywall screws and attach it to the bottom half with the srews down thru the top half into the bottom half. I put 1 srew in the middle of each of the 4 pieces. Let cure, then disassemble making it very easy to get the mold out. Clear as mud right. lol