Terry, You can also try making 1:5 top and bottom portions and half baking (15min cure at 70-80=B0C) a 1:20 layer between as a glue layer. This = can be applied via spin coating, although if you don't have one available, you can also lightly smear it on with something that has a reasonably straight edge - e.g. a coverslip, slide, or even a piece of office grade overhead transparency. Lee Pang wpang@ucsd.edu