◆◆◆ BackgroundThe Risograph is a cost-effective and environmentally-friendly digital duplicator that creates unique prints by layering soy- and rice-based inks. I like to think of it as a cross between traditional screenprinting and Xerox. The machine itself looks very much like a run-of-the-mill copier you’d find in the corner of a dusty office, but the vibrant and unique prints it can create has drawn artists and designers to it like flies to honey. Risograph as an artistic medium is only a decade or two old, so it’s still somewhat niche and not very well known in the broader artistic sphere. With its ability to make many prints quickly and for relatively cheap, along with its imperfect and tactile aesthetic, Riso lends itself incredibly well to book- and zine-making, which is why it is heavily utilized in the world of art books, comics, DIY, and zines.
◆◆◆ How it WorksRisograph printing is comparable to screenprinting in that its vibrant inks are printed in layers by pushing liquid ink through a mesh screen, partially blocked by a stencil that contains the image information. While photoemulsion screenprinting requires the image to be only black and white/pre-bitmapped by the artist, the Riso has its own very fine bitmapping technology, so the image being scanned or sent to the machine can contain the full spectrum of grays—from 0% to 100% and anything in between.
◆◆◆ Printing ProcessFirst, this grayscale “original” is scanned on the glass top of the machine (or sent digitally, straight from a computer). Next, the image information is read and bitmapped by the machine, and a stencil is burned into special thermal paper creating what’s called a “master.” This stencil is then wrapped around a cylindrical ink drum inside the machine, and as paper passes through the Riso, the ink drum rolls, pushing ink through the drum’s screen and the freshly-applied master covering it, thus leaving an inked impression on the paper. Each ink color needs its own drum, and—when making a print with more than one color layer—the drum needs to be switched out, another master made, and the same paper fed once again through the machine.
◆◆◆ LimitationsThe max image area is 16.75 x 10.75". The max paper size is 12 x 18".
When printing double-sided, it’s best to avoid heaving inking on at least one of the sides to minimize smudging and paper jams.
Risograph ink is not lightfast and never fully “cures”—heavily inked areas are likely to smudge onto fingers when handling, long after the original print date. The ink washes off easily with handsoap and water and is non-toxic. This should be kept in mind when designing works for Riso that will be frequently handled, like the covers of zines/books.
Occasionally (especially if the image has high-density areas and more than one color layer) prints will exhibit roller marks and/or ink smudges. On un-inked areas of the final print, these artifacts can be lightened and partially eliminated by carefully using a soft pink or white eraser on them.
Flats of color may not print an even tone. Particularly with large, flat areas of color that have a high ink density, the appearance of what’s called a “tide mark” is typical. The ink density from print to print may also slightly vary throughout different prints from the same edition.
Misregistration is extremely common—it’s all but guaranteed on at least a handful of prints in any given Riso edition. Registration issues can be mitigated during design/separation by using “trapping” between color layers.