Pretreated papers

If a paper has already been pretreated chemically with a substance or processed physically, it can cause problems inside the device. Chemically treated or coated paper (such as thermal paper or carbon paper) may cause the paper not to be fed in as smoothly or the paper feed to work incorrectly, causing the paper to skew, curl, or not feed at all. It is important to test edition prints in advance when using a paper like that.

It is also crucial that the papers are not rolled or folded before printing. Papers with adhesive strips (e.g. envelopes) can take on ink and get stuck on the colour drum because of a reaction, and even perforated or punched paper can get caught on the drum. If possible, the papers should be stored in a dry and dark place. Exposure to sunlight can negatively affect not only the paper colour, but also the surface smoothness, at the expense of the printing result.1

  1. Riso Europe Ltd., RISO MZ Series. User’s Guide 970/770 (London: Riso Europe Ltd., 2005), 17.