Photoresist Update
Morton has discontinued the 100-foot rolls of the Laminar resist I had been using, and now sells in 250-foot and longer rolls only. For any experimenter, most would be wasted after the 1-year shelf life.
Think & Tinker sells 50- and 100-foot rolls of an equivalent resist--Riston, made by Dupont company. T&T sell over the Web, take credit cards, and have excellent products and support.
I bought a roll of Riston from Think & Tinker, and it works beautifully. It laminates very smoothly, develops cleanly and strips nicely. Actually, just about like I remember with a very fresh roll of Laminar... They are really about identical, other than the exposure time, which is significantly longer.
For 11 clear brass (on the 21-step Stouffer exposure wedge), the Riston needs about 5.6 minutes exposure with the T&T lamp setup. The equivalent exposure time for the LM-10 was 2:30.
