I once did a process of making the masks black and white on a Mac computer
using a drawing program. Then I would take the disc to a service that
printers use and have them make a mask of emulsion on a clear mylar sheet.
The tool they used was some cool laser printer and it did the developing as
well. This was good enough for me to use standard wafer photolithography to
transfer the image to a substrate. Using deep contact printer I was able to
resolve 2 micron features. Worked well for the images I was transferring.
Good Luck

Bob Henderson