Bill, thanks, I tried something similar to this with Durimide Polyamic
Acid.  I spin-coated the solution on glass and then tried curing the
samples with a sheet of Kapton on top in either N2 or forming gas. The
polyamic acid turned opaque in a few regions and would not bond to the
Kapton - I think this might be due to trapped gas between the Kapton and
spin-on polyimide.  A control sample without the Kapton sheet did not turn
opaque.  Any thoughts?