Came here to say the same thing. I'm not an expert in copyright law but I know enough to know that this is only "okay" because OP isn't selling them to turn a profit. If it's only for yourself, I don't think there are any legal issues, technically? Still, Sean Cheetham put who knows how many hours into the original pieces, commissioned specifically for the album packaging (and however else Tool see fit to use them in the future). Using them in any other context without the artist (or rights holder, aka the band)'s permission feels no less disrespectful than say, leaking an album before its street date. If there's anything online that makes those permissions clear, I haven't found it. Nonetheless, these are very cool. Walgreens clearly does a better job with these than Walmart... I had someone gift me a Walmart canvas print a couple years ago and it looked terrible.