I received a email from WWW.Smooth-On.com
with instructions on how to paint urethane rubber.
it gives me an idea or two, Hope it helps some of your projects
Full story here http://www.smooth-on.com/gallery.php?galleryid=421
Using Brush-On 40 To Paint Urethane Rubber
Urethane rubber is an excellent choice for casting props or costume pieces which require high abrasion resistance and durability. The challenge is finding a paint which will adhere to the surface of the urethane casting.
Some of our customers have found that our Brush-On 40 urethane rubber has excellent adhesion properties and can be used as a paint for urethane rubbers when combined with So-Strong pigments and thinned with mineral spirits.
The pigments must be added to the rubber before the solvent is added, and for this reason, small batches of rubber should be mixed.
In the following example, Brush-On 40 is thinned with mineral spirits, brushed and airbrushed onto the surface of a Reoflex 30 casting.
The frog was cast into a Smooth-Sil 910 mold, making release agent unnecessary. If a release agent were used, it would need to be thoroughly removed from the piece using an appropriate solvent before a casting could be painted.