Thanks for the numerous responses although I remain in a bit of a quandry because:
1) I wasn't aware that there was any requirement for resetting the paper thickness value - I didn't see any reference when I consulted the PDF manual for the printer.
2) I'm using the Photo Black cart because... that's what it says in the instructions.
3) The roll of canvas was supplied to the purchaser directly by Epson, so one assumes it's a current example.
I must say that ploughing through ink in order to test all possible options is a big deterrent. Also, assuming I were to cut down some stock for testing purposes - say 6x4 - is it going to reliably pass through the paper path? I ask because the large sheet which I fed through initially (cut down because I have never used roll-fed paper even when printing landscape panos) almost jammed up before emerging due to upward curl - I just caught it in time. I should point out that I fed the canvas sheet via the top sheet feeder. My immediate inclination is to forget about printing on canvas completely, I'm not entirely convinced about it for photographic reproduction, although I'd like to see what my own material looks like first.
1. 2400 was not designed for canvas although it should work quite well which is also why you do not see anything mentioned about canvas in the pdf. Its alot thicker so check your settings especially the platen.
2. It says PK ink for the Matte canvas? I would double check that one.
3. To the best of my knowledge it is discontinued which makes it not very current. (Although it should still work.)
Tape a leader to the front edge if it is hard to feed,that should fix that problem.
To address your present problem pop in that mk cart,change your profile and see how that goes. Still think you have a ink and also a profile mismatch.
Canvas for photographic reproduction is about as good as it gets. My entire business model is setup around canvas.
Buy some samples of the current canvas offerings,download the profiles and print away.
If you like the canvas printed output you have only just begun.
Next is varnishing,spray or roll and then mounting. More work then paper prints but so worth the effort.