The Risograph will add a halftone to photographic images so you don’t need to do any bitmap print.
There are two options to choose from:
- Grain Touch: a randomized diffusion dither pattern (like a photo or film grain)
- Screen-Covered: creates classic halftone patterns.
- Screen Frequency controls the size of dots produced (higher numbers = smaller dots).
- Screen Angle controls the angle that the pattern is set to.
Registration & Trapping
The Risograph has limits of accuracy. Each color layer requires a separate pass through the printer, registration on multi-color Risograph prints will never be perfect.
It is recommended that you add registration marks to your image to aid in lining up multiple layers. These can also double as trim marks if you plan on cutting down your print to size.
Surfaces should overlap under lines. Otherwise, white gaps may be visible in your artwork.
Line work printed over solid blocks of color will usually look best.
Trapping is the practice of adding a little bit of overlap between adjacent colors to make sure that there are no white gaps between them even when registration is a little uneven
Overprinting vs. Knockout
Overprinting: is when colors are printed over each other. This creates new colors as the colors are blended.
Knockout: is when you cut out overlapping colors from the lower layers so that you only print with the pure spot colors.