Risograph Printing in the Knowledge Lab

RISO printing is a spot color printing method, meaning that it excels printing individual colors, as opposed to mixing all CMYK color inks to reproduce a wide range of colors like inkjet printers. Risograph ink is semi-translucent, so the final appearance of a print depends on the color of the paper used, the layering of each ink, the saturation of color (10%-100%), and how the overlay of colors can mix and create new colors. 

The RISO printer can only print the color of the ink drum that has been inserted into the machine so information sent to the printer needs to be converted to grayscale (more details about this in the File Prep tab). Prints can be made with a single color (monochromatic) or multiple colors can be printed as separate layers by changing the ink drums and putting the paper back through the printer. 

RISO ink dries through absorbing into the surface of the paper and never fully dries, because of this, prints fresh off the press are susceptible to smudging and ink transfer. Be careful handling prints and wait to fold or trim until the prints have had a day or two to dry. If printing multiple color layers, it's best to wait at least one hour to one full day before printing the next layer. 

Two color, three color, and CMYK?

RISO ink does not perfectly correlate to traditional printing inks or pantone colors. You can choose to print any color combinations you want and enjoy the unique and unexpected effects that come from layers of color interacting with one another.

Full color images can be reproduced through CMY or CMYK color layer separations using a program like Adobe Photoshop but the final image will not be a true reproduction of the original image. Of the inks available in the Knowledge Lab, CMYK is usually printed using Cornflower Blue for Cyan, Florescent Pink for Magenta, Yellow, and Black(Key). 

Things to consider when creating multi-layer prints:

• Prints can't be more than four layers. 
• Print layers starting with the layer with the least amount of information and ending with the layer with the most amount of information. 
• Make sure to jog the paper stack tightly before putting back through the printer and position the paper in the loading tray in the correct orientation. 
• The more layers printed, the higher the chance there will be issues with registration. Some level of misregistration is a normal aspect of the risograph printing process and should be expected.
• The more layers of ink needed, the thicker the paper needs to be to absorb the ink. For example, do not make a 4-layer print on 20lb copy paper, use at least 70lb text weight or cardstock.