What is riso-printing?
Risographs are duplicator printers from Japan that function similarly to photocopier machines, and utilize a process similar to offset & screen-printing.
Risographs create stencil/image “masters” that are applied to cylindrical ink “drums” to print spot-colors. Each ink drum contains a single color, & the masters are made from color-separated files/images.
This process is similar to the way that offset printing uses plates for each spot-color separation, & the way screen-printing uses stencils on emulsion-coated screens to print one color at a time. Risographs are also alike photocopiers in the size/appearance of the machine, & through its ability to print from sending a grayscale PDF from the computer or printing off the scan-bed.
File Set-Up:
Each color separated PDF has to be in grayscale in order for the risograph to print it. Risographs read grayscale PDFs as opacity ー higher/darker opacity (i.e. 100％ or black) results in a denser print & ink coverage. When setting up a file, all lines or artwork should be trapped when possible to avoid a halo effect with mis-registration (example below):![]()
The registration while printing on the risograph (especially in multi-color prints) is never fully spot-on; trapping the images/artwork helps make the shifting & variations in the printing process less noticeable:![]()
Some other helpful guidelines when setting up files for riso-printing are to avoid large flat & dense areas of ink coverage, especially at the lead edge of the paper ー it will cause roller marks on the prints from the ink catching & smearing on the paper feed tires. Also, avoid overprinting key line art & text ー always keep it in one layer/color-separation.
The maximum printable area on the SF9450 riso is approximately 11”x17” (297mm x 432mm). The artwork or file should not exceed about 10”x16”. When printing a smaller file like postcards, the artwork should be laid out in multiples on a 10”x16” document to maximize the number of prints per sheet of paper.
Riso Process Color & Duotone/Tri-tone Printing:
Unlike commercial printing processes, risograph printing utilizes spot-colors instead of CMYK. To print photographic images on riso, 4-color CMYK color-separations are replaced with different riso process color (spot-color) combinations for duplication, resulting in totally unique & fun prints. In the Other World Riso color setup, cyan is replaced with federal blue, magenta with raspberry, and yellow with light lime. “K” or black remains the same.
✰please visit
“www.otherworld-riso.xyz”
on a computer...✰
“www.otherworld-riso.xyz”
on a computer...✰
