I buy mine from Fargo Plastics. Any of the larger plastic suppliers would carry it McMaster Carr has it but you will pay a premium there. As far as turning loose as long as you sand it (80 grit) and use Weldwood landau adhesive you won’t have a problem. Make sure you sand your foam before bonding too.

I use plastic xmas tree type fasteners. Panels are double layer pvc so the heads are not visible when the panel is attached

For what it's worth for other guys out there wondering the same question i did I used #3 cross link foam for the sculpting. I wish more trimmers would share to their fellow friends on here . And thanks tou all of you that take time to post the tutorials.

Yes back it with the material you want to use same color or different like your photo then glue both pieces to your sew foam

the laseris a great tool I use mine for tons of fab patterns on consoles and door panels . Usually use abs and use it to rout out parts. Also I cut my material on repeat bomber seats. Even engrave patterns on the material.