Yo, Bill! It works great on canvas! Got one today and after downloading the version 3.0 software from their website (178mb) it even works on my Vista 64 system. The software that came the DVD did not work.
So after maybe 10 minutes of manually moving the puck from patch to patch on the printed target, I got a profile that simply beats the heck out of the 3 commercial profiles and 2 canned profiles I have been trying to make work with Epson Premium Canvas Matte. That little Spyder3 puck is giving me super matches with the screen, no more having everything below RGB value 32 or so falling into saturated black, no more ridiculous printing compensation curves. Woo hoo!
And all those rolls of BC Chromata White with the nice bright colors and absurd canned profiles that I was going to sell on ebay is now entirely usable!
So why do all those canned profiles print so dark? Is it Vista 64 color management...the wide gamut LCD...wishful manufacturer's profiles...or what? Ask me if I care anymore. I feel good.
All you guys crying about prints too dark should maybe look into doing your own profiles.
