Hi Mark
I always work on linen (or canvas) stretched on panel - I've always preferred a firm surface to work on and cant get along with smooth panels of any kind.
I must admit I generally get them made up by a professional canvas maker, especially for larger sizes (it's a job I dont relish and find its much better done by a professional and frankly worth every penny its such a stressful job to get absolutely right I think - let alone having a clean flat surface big enough to produce the large scale versions)
I've used up to 48" x 60" versions with no problems so far and as I'm using approx a 5mm marine ply as the support it doesnt end up too heavy at all. In terms of ease of hanging, I use a heavy frame so it gets additional support there but panels can be cradled if need be to counter warping (theres a thread somewhere in the forum about this...) and can be fitted with wall mountings so as to avoid the need for a frame if preferred.
Recently I have just started to use Dibond aluminium panel (you have a similar product in the states called ABS I think) which I like a lot certainly at up to about 30" x 30" its worked very well I've stretched the linen myself, I use a few layers of acrylic gesso as the adhesive (its stable and I'm told can be removed later if need be - and I have done a few tests to try this without too much trouble) but if you choose to stretch your own and don't fancy gesso you can get hold of some BEVA archival adhesive as used by fine art conservators (the process is detailed here:
http://www.welshartsarchive.org.uk/a...els-burton.htm)
Pheww... hope thats a start anyway!
Best wishes
Mary-Jane.