Joe Grogan,

Best way I found to get thin PDMS off of photoresist on silicon molds was
to dunk the whole thing in ice water - cold contracts the mold and the
water swells the PDMS. A minute or two and it peels right off intact.

Those were 30 microns thick layers. If you have adhesion problems, I found
that coating my mold with acrylic enamel paint worked well.

Mike