I made a gelli plate that is not supposed to mold or have to be stored in the refrigerator. I used 9 gelatin packets 2 c water and 2 c glycerin to make a plate that is about 9" x 12" x 1/2". It cost me about $10 to make it. They say that you can cut it up and heat it in the microwave then re pour it and use it again if it gets messed up. I found out the hard way that it is a fairly fragile surface, because I used a plastic lid to a coke bottle and it scratched it up. I did remelt it and the second time it came out just as smooth as the first time. I made it on Thursday morning, messed it up and remelted it on Thursday afternoon and have not refrigerated it. This is Monday, so far so good.
I don't know how many times you can do the remelt thing, but I will let you know how it goes. I wanted to see if it was something I enjoyed using before I invested more money in a bought one.
The picture of the gelli plate is after cleaning up from my latest use. I used it once, about twenty prints, and messed it up and remelted it, and then my daughter used it once about twenty prints and then I used it again for about twenty more. The bubbles in the plate are air caught under the gelli not a defect in the surface.