If this is the vintage 7500/9500 I think you are out of luck for cutting other than paper.
I had both a 7600 (a newer model than the 7500 as I recall) and replaced that with a 9800 for larger prints and better inks. Though it printed faster/better than the 7600, including canvas, it required hand-cutting as the auto cutter was too wimpy.
I looked into the cutter for the 9800 for canvas but it cost more than the printer was worth, was manual and with the project I was starting simply decided to replace it with the 9900 which has a beefier rotary cutter that was rated for canvas. A few thousand canvas prints later, it's still going strong.
Pretty sure anything prior to the 7900/9900 probably would choke the cutter when using it to auto cut most canvas. Each model newer also prints faster, at least twice the speed as the former and I think that my 9900 is considered slow today compared two the two newer models that have replaced it.