Schools have asked if it is possible to make ditto masters with the ImageWriter II. Apple has suggested removing the ribbon from the printer and moving the forms thickness lever back to the third or fourth position. This is supposed to help keep the print head from damaging the fragile master. The problem is that this method keeps the printer in single color-mode which, in most cases, doesn't transfer enough ink to the master - not from the non-existent ribbon, but by the impact of the wires - to produce a good image. This is due, in part, to the density of the actual top page of the ditto master itself and the size of the wires in the head of the ImageWriter II.
Here is another method - one that will improve the quality of the ditto master:
1. Remove the ribbon from an ImageWriter II color ribbon cartridge.
2. Insert this empty cartridge in the printer. This will close the color micro-switch on the carrier assembly, and fool the printer into believing it has a color ribbon installed.
3. Through your software, tell the printer, via control codes, to print in either Orange, Green, or Purple. Because these three colors are normally created by making two passes with two different colors, and the printer believes it has a color ribbon installed, the print density will be doubled, improving the quality of the ditto master.
Without the color ribbon installed, and with a color selected that requires two passes to create, the printer will effectively be in double strike mode, which is not a selectable mode otherwise. With double strike, the dots are almost completely re-struck, which produces a better image while not abusing the ditto master itself. (Boldface could be used but that mode does not overstrike dots completely, rather it strikes a dot that partially overlays the previous dot, which produces a broader image that may not be acceptable on ditto masters.)