Hi all I’m trying to find out if there is an easy method for seeing developed SU-8 through another layer of SU-8. We are trying to make devices requiring double depth processing and the aligning of the photomask for the second layer is very difficult as we are currently unable to see the developed SU-8 on the bottom layer. At the moment we need to overdevelop the bottom SU-8 layer until cracks appear at which point we can see the cracks through the top layer of SU-8. Any suggestions would be much appreciated. Thanks all Matt Davies STRC, University of Hertfordshire --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.738 / Virus Database: 492 - Release Date: 16/08/2004