The Form 2 can print 25 micron layers as it builds a part, perhaps thinner if the speed/power of the laser were adjusted. We are trying to print a single layer of resin onto a glass substrate sheet. Any thoughts on how to do this. We have tried with limited success to print a platform with supports and then pause the process and mount the glass sheet. Limited success. Also we have paused the process and laid a sheet of glass into the tray for the laser to print a single layer then paused again to remove the glass. Messy but better results. There are a number of very interesting applications if we can do this.
Might be good to have an empty tank, paint on or dip the glass substrate in the resin, and then forcibly push that glass resin down onto the empty resin tank. Run it in Open mode without a build platform installed and it should run the laser pattern you want. Not sure how you really control the thickness of the resin though. Maybe try putting different weights on top of the glass so it will squeeze out a different amount of resin when you place it face down. I assume you can put a 25 micron STL into PreForm, arrange it without supports and print it but I have never actually tried.
Check out the thread on here that does the PCB layout since it seems similar.
To control the height of the layer you could try to put for instance a PE-fillm or adhesive film between the glass and the silicon. If the layer will be uneven you could try to add more film on one of the sides.
You’re going to have an incredibly hard time trying to print a thin layer. First layers don’t have an accurate thickness so that it can account for the platform not being level with the bottom of the tray.
What’s the reason of doing this?
I think it could be possible to design for instance lamps by printing art on glass and shine light trough the glass plate, however there could be probably a more simple way to achieve the same effect with other techniques. 
If you do ever get the layer to cure on the glass, you’re going to have a hard time getting it to stay stuck for more than a week, especially if it’s under normal wear and tear.
I would suggest building a layer of tape and spread a thin bit of resin over it and let it cure in the sun to test it out. Then work on the hard stuff like printing designs.