Hi Sharon,
I've been on a quest for coming up with large drawings that don't need to be protected by glass.
I've posted about preparing ABS panels on this thread:
http://forum.portraitartist.com/show...&threadid=2906
So far I've experimented with a combination of Nupastel and Charcoal. The biggest problem, of course, is that the ABS surface can't take a layers of drawing medium. The other problem is that sanded ABS will eventually yellow with exposure to UVA rays unless it's covered with a layer of media. After pulling out white highlights I went back in and put white Nupastel in to protect the ABS surface. I plan to spray varnish this to see what happens.
I'm posting a detail of a large panel.
I was on a Sir Henry Raeburn quest all summer, tracking down his portraits all over the east coast. I love that whole swashbuckling, British commmander costume look. Would you believe me when I told you I saw the movie twice just to see the clothes? (I knew you wouldn't.)
Hold Fast,
Linda