Yes, I think your assumption is correct. I have done exhaustive research and talked to many Canon customer service agents and was told different things. At first I was told that all the papers labeled Pro "Premium" were acid-free. That would leave out Pro Luster which has no "Premium" in its name. Based on this, I bought a lot of Pro Premium Matte and really love that paper. Only to find out that NONE of the Canon "Pro" papers are acid-free. The only Canon papers that are acid free are the 100% cotton papers, and yes, they clearly state acid-free in the specs. That's a big selling point, so if you don't see it in the specs it is not acid-free. Now I've got all this Pro Premium Matte and I'm left with the unanswered question, what is the longevity of this paper?
Canon does not even list Pro Premium Matte with the compatible Chromalife 100+ papers. So it doesn't even measure up to those in longevity??? Direct quote from Canon's Chromalife 100+ webpage description: "ChromaLife 100+ compatible photo papers include: Photo Paper Pro Platinum, Photo Paper Plus Glossy II, Photo Paper Pro Luster and Photo Paper Plus Semi-Gloss." Why not Pro Premium Matte???
To say I am baffled is a gross understatement. I am left wondering if Pro Premium Matte has much longevity at all . . . 5 years? Less? I wish someone from Canon with real knowledge of this product could answer this question.
And btw, Canon Premium Smooth Fine Art paper, acid-free, was just discontinued. Don't understand that either.
Thank-you for your responce! This is super helpful info, but as you say, it also brings up many further questions.
I though someone from Canon told me some of the papers were acid-free but I couldnt remember exactly. That you also got conflicting info from Canon makes me think I'm not just mis-remembering.
Other paper companies have pdf's detailing all the specs on their paper. I wish canon did this.
I'd love to hear from an official Canon rep on these matters.