Thanks Ernst, I had started to resize each print manually in Qimage, which is a pain. What was puzzling me was I had the problem even after cutting sheets from a roll of canvas and letting them relax for a day before printing.
The print driver only seems to allow a percentage resize in all directions, and even then only by integer percentages.
When I asked Mike to add a canvas wrap feature to Qimage a long time ago the request wasn't honored then. So I made the Canvas Wrap Actions for Photoshop. I'm glad I did as it can change aspect ratios and has more features than what Qimage at last got for wrapping. A RIP or a driver that compensates the length issue on the fly is nice but should allow adaptions to the canvas one uses.
There have been more discussions on what actually is the reason for canvas print size differences. Maybe it isn't tension on the roll but media transport acting different with fabrics. In the end you create a workflow that is based on one or two canvas qualities, printed from the roll and you cherish an opinion on what the reason could be for the length differences:-) The economy in canvas printing starts with different roll widths, left over sheets are usually just not big enough and for proof sheets a glossy paper works faster. But if you turn your sheets a 90 degr. and still get shorter print lengths then it can only be transport to blame :-)
Barry's experience is different and the percentage of added length quite high so I doubt that a canvas media preset has overdone its job for him. More likely a Z driver quirk like it can happen sometimes. With Qimage I have had strange effects with image crops on proofs but they have been taken out after my bug report.
met vriendelijke groeten, Ernst Dinkla
Dinkla Gallery Canvas Wrap Actions for Photoshophttp://www.pigment-print.com/dinklacanvaswraps/index.html