I poured some baits for the first time on a custom mold that I made with fiberglass resin. Unfortunately, the model baits began to float and making most of the mold useless. After they cooled, I put them down on glossy photo paper and they fused to the paper. I tried this with other baits (yamamoto, yum, etc) and they also fused. It seems the softer the plastic the more they bonded. I ended up having to rip them off in pieces. It felt like it was on fly paper. I wish I would have known about this before so I could have placed all of my model baits on glossy paper and placed the paper on the bottom of the pan before I poured the resin.

Why aren't you pouring the mold in halves? Can't you pour some resin, put the bait down in it half way, let that dry, then pour the second half?

I have no experience doing any of this, but that's what I have seen others do in tutorials

I'm doing flat sided baits to start. I sthere a better casting material than fiberglass resin? That stuff smells really bad.

Seems a lot of people use RVT Silicone for molds. I don't know if it's easier or less smelly than Fiberglass Resin though lol Sorry I'm not much help!

I glued the copies to the bottom and poured the resin.  They came out better than the water cured silicone I tried.  The RTV like was posted, is better, but I haven't used it yet.