As per melinex, it is interesting to think that we invented these materials within the last 60 years (+/-) and therefore how can we really know if they'll last. Hopefully though... because I just bought a 1000' of polyester film sleeving.
PE, I get the feeling that you and Henry Wilhelm don't agree on some things ? ? Also, when talking about longevity, you're mainly questioning the support, not the carbon colors themselves, right?
To me, the idea of using a high quality artist's paper is the most fool proof in terms of longevity. This, we know about.
When transferring the carbon layers to the UltraStable receiving film, does it adhere to the pure melinex, and the opaque backing is on the other (base) side? Or is there an opaque subbing layer on the carbon/"emulsion" side?