Recommended Paper Backing and Print Process for Soft Plastic

Hello all, I've been having trouble finding a proper paper/toner combination that won't stick to soft plastics. Hopefully someone here who has more experience in this area can be of assistance.

I've used a laser printer to print on the following:

14 Point Matte Card Stock - Low sticking to soft plastic when laid flat some toner rubs off onto soft plastics.
14 Point Gloss Card Stock - Pronounced sticking to soft plastic when laid flat some toner rubs off onto soft plastics.

It seems to me that the toner isn't curing properly this is the result after the paper has laid for 24 hours before any soft plastic items are placed on top.

My question is what materials/printer would work best to do the job? Do I need to use something other than a laser printer? It's important that the paper/toner/ink doesn't react to the soft plastics? I'm not seeing this issue with Hard ABS plastics.

Thank you,

Effatory