The format table above shows that almost all risographs can easily print in A3 using an A3-sized drum. Since the RISO A2 is still quite rare, but A2 is a popular format for printing, it is possible to let the sheets presumed to be too large still pass through the machine using some tricks: The sheets are folded before printing to make them smaller, bringing them to the size required for the machine.
If the sheets are folded afterprinting anyway (to process them further to a newspaper, for example), this production step is simply done earlier. After a print run, the signatures can be printed on from the back and eventually be reversed (turn the outsides inward) to print on the inside of the signatures as well. Make sure that these sheets are not heavier than 100g / m2 to avoid paper jams: these multiply folded sheets become real heavyweights for the risographs. The sheets should not be too thin, as the risograph might wrinkle or even tear them apart when they are inserted. Depending on the grammage, a thin paper can be placed between the already printed areas on the inside of the sheets to avoid them from rubbing off on each other.
The signature of the sheets is definitive, which is why no trimming can be made on this side. The signature is not bled off after being wetted with colour either due to the way the printer works, because despite the larger format, there are no options for borderless printing. Even with a size slightly smaller than A2, borderless printing is not recommended because the sheets at the signature can become soiled heavily. When doing the final artwork, it should be clear that the layout to be printed is folded orthogonally to the broad side of the sheet.
For this purpose, sheets with the direction of short grain offer an advantage when printing. This trick, of course, works not only for A2-sized sheets, but also for the format A1. While the sheets are folded twice before printing, a blank sheet can be put inbetween to prevent the abrasion of fresh ink. The sheets should be at least as light, if possible even a little lighter (90g / sqm). When printing these sheets, make sure to lightly press down the sheets inside the paper feeder with your hand so the risograph does not have any problems with the stacked signatures of the papers and the edges of the paper pile in the paper feeder differing in height. Slightly pressing down the side of the signature helps guide the sheets correctly as they move in, which greatly increases the chances of high quality printing.