Hey! I make big prints on canvas because it's the only sane way to make really big prints! No glass, just for starters! That's exactly the reason oil painters use canvas, although many of them would actually prefer to be using board. And the only way I could TRULY distinguish my photography as a unique art form is if I was making Daguerreotypes which is just too boring.
The majority of the public has no acceptance problems at all with photos on canvas versus oils on canvas, they just buy the image that moves them the most. Or the art that best color coordinates with the sofa...
Bill - I agree. The reasons i went to canvas were not to imitate painters, but:
a. weight, large canvas prints are much easier handled and transported than traditional framed prints.
b. Some show organizers don't allow glass over prints, especially if its going to be mailed in. I had a 1' by 3' framed print that the customer dropped while taking it off the display wall. shattered the glass and frame - whoops - don't want that now :-)
c. Reflections - its so nice to be able to view a print without all those reflections on the surface that come with glass and even plex to some degree. Museum glass is so expensive.
d. As far as "purity" goes, a lot of painters are scanning their paintings, and using that digital jpeg to make additional ink-jet printed "painted" canvases. There's nothing wrong with that, IMO, but its certainly not "traditional" to use ink jet printers for paintings.
e. I just got back from an artist's reception at the Edmonds, WA, art and crafts fair. I'd guess about 10% of the photography was in canvas, at least i can remember 5.
f. In April i had a show of 16 canvas prints in Port Townsend, WA, at a local shop. I sold 4 prints, and 5 members of the adjacent co-op gallery came by during the art walk night to invite me to join their gallery. Canvas is still not going to sell your prints if the content is not there, of course. And it does raise costs. I belong to the PT Photo Club, and members there have been very supportive of canvas, a few going that way themselves.
g. Printing on metal sheets is the newest thing, but that really is expensive.