Eggbox material is a bit flimsy unless used with resin to lock the shape in, then it (on my molds) wants to lock onto it plus you need a male and female to keep the original ribbed look, I've got the female mold and 1 male mold , as soon as I get the plastic one perfected for use, I'll cast a hard epoxy male and female mold to try it with the original style /type material , I can guarantee it'll cost a lot more to go back to paper type due to the labor and length of time you have to leave it in the mold to cure