I did a ton of work to learn to do halftones with a Caprock halftone screen. From a Kodak book, I learned about the highlight bump exposure, then the main exposure, followed by the shadow exposure, which was a darkroom safelight with a yellow bulb, on a stand. We had a horizontal camera, and the vacuum back opened to the right. So after the first two exposures, we'd open the door so it was 90° to the wall, move the yellow lamp into place, and make yet a third exposure, which would open the shadows with very little effect on the midtones or highlights. Arcane enough? I really can't thank Adobe enough for publishing Photoshop.
Regarding Autotype's PhotoStrip, if I remember correctly, you put the positive on the backing side and shot through the back. Any of you older guys remember that?
Steve