To understand the role that paper plays in Risograph printing begins with a brief knowledge of ink behaviour. Soy-Based Risograph Ink dries through a combination process of absorption and evaporation, so it is ideal to find paper stocks with qualities that suit this process. Much like soy-based newspaper printing ink, Riso Inks may smudge after the prints have dried (technically, the ink never really sets). This may be of concern for some projects, especially those with heavy ink coverage, or intended for handling.

Procedure for converting the color of a Z-type drum. Steps 1 - 9 also work when machine does not recogonize a correctly installed ink tube.

There are several Risograph Z-type drums, most of which are not universally compatible.
Use the following charts to determine compatibility with your machine:

North American Models

RZ 590 & 390 Compatible

MZ 790 & RZ/MZ 990 Compatible but Drum Code Entry may differ
         MZ 790 Drum Code Entry (Test mode #1210): 69
790 can be converted to MZ 1090 with special kit