Have seen the Cripplebush Valley Models rubber rocks at train shows and talked to the owners/artists. very nice product and flexible in use.
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/
DeadheadGregCripplebush makes some REALLY REALLY great rubber rocks... you can bend them and flex them, but they look just like plaster if you didn't know they were rubber. AND they come colored.http://www.cripplebush.net/
I used rubber rocks exclusively. The pre-painting is terrible but nothing a few washes of latex paint and some drybrushing can't fix. Sooooo much better than the PITA plaster cast method.
San Dimas Southern slideshow
Cripplebush makes some REALLY REALLY great rubber rocks... you can bend them and flex them, but they look just like plaster if you didn't know they were rubber. AND they come colored.
http://www.cripplebush.net/
There were a few different rock face types that I saw. Squeezing the package it felt like a medium foam. Supposedly there are instructions on painting in the pack. It comes with a brownish color but can be painted with recommended acrylic or enamel paints. Size seemed pretty good, about a foot or little longer, by about 10 to 12 inches high.
Springfield PA
Interresting! I would have some questions though before I ordered it. You have an advantage, you've seen it in person.
How large is the piece?
Are their other types of rocks?
Is it always the same color?
Does it take paint/stain?
Does it cut easily?
Let us know if you try it, as I said, it sounds interresting.
Have fun,
Good Evening
Anyone here ever try this product?
http://www.hobbylinc.com/htm/isl/isl501.htm
I saw it today at a LHS and it looked pretty good. Looks like it's made of some kind of foam.