Sharon, when you say ABS absorbs moisture and warps, do you mean it turns and twists along an axis (is this torque? Oh, I am way out of my league here...). Would it not behave itself in a frame, like a zaftig lady in a corset? Or do you mean that it puffs and bulges like a sponge? Wouldn't it be better to absorb moisture rather than dry out, crumble or crack? Would it absorb moisture just by hanging around on the wall, or would you have to leave it in the rain or bury it underground (oh I do hope my paintings don't have to go through that).
The very thin ABS is pretty cheap, around 25 dollars for a 4 x 8 foot piece, and I can cut it up with a utility knife to my specifications. I have some of this lying around on which I will probably use oil paints. The thicker stuff is more expensive but needs no backing to work on. To me, one of the great benefits of working with plastic is that I can sand off a mistake or even an entire bad painting if I feel like it. I just finished a self-portrait (here's the link to it on my website:
http://www.lindatraceybrandon.com/bio2.htm ) where I started off with a white skirt and ended up with black slacks after sanding. I wear a mask when I sand this stuff.
I like the idea of mounting a beautiful Twinrocker paper onto Gatorfoam (can I do this myself? does it need to be professionally mounted?).
You know, I think that grounds in general deserve more scrutiny than they generally receive. So many people use linen because of its long history of use, but I see so many old paintings where the linen has crumbled, become moldy, suffers cracks, holes, insect damage, you name it. I appreciate what Virgil Elliot is doing with paint pigment permanance and I'm conducting my own primitive experiments with putting paintings and pastels in the sun; the pigments hold up pretty well. It's everything underneath them that is going the way of all flesh.
You are an amazing resource to have on this Forum. I bless Cynthia every day for providing the magnet that attracts passionate, opinionated, determined and obsessed artists willing to share arcane information.
I'm off to my lair to brood and putter, visit websites and make phone calls. Tomorrow I'm seeing a flayed cadaver as part of my anatomy study (happily, this won't be taking place in my studio). If I don't get sidetracked by this experience I hope to tackle my plastic dilemma as soon as possible.