Test NegativesRalph.. I bought a mask made for semiconductor manufacturing. It is an old item, so of no commercial importance. The lines are etched on with accuracy to 5 microns. It is a B+W Mask only of a geometric pattern. It works quite well if you are only interested in alignment. The mask is so accurate, that any error is in your setup. You can examine the projected image on the baseboard or make prints and check them out. It is thin glass, about 6 inches square... I got it from http://www.goldmine-elec.com The item I have is about 10 years old, but they still have them in stock...... http://www.goldmine-elec-products.com/prodinfo.asp?number=G14259&variation=&; aitem=2&mitem=2 BTW, they claimn the masks are .5 inches thick.. no way.... they should be around 0.100 inches thick or thinner..... It may or may not do what yo want, but it is only $12.......! Frank Filippone red735i@xxxxxxxxxxxxx