What is RISO?
RISO is a Japanese brand of duplicators and printers. When people talk about risographs, they usually refer to the duplicator series of printers. They are quick, easy and cheap to print from and perfect for mass printing.
The RISO machine itself looks kind of dull, almost like a big old copier. And that is, because in some ways, it is.
It was originally used in office environments, schools, churches, sporting clubs and political parties to quickly print multiple copies. Whether those were announcements, letters, pamphlets, or posters, the RISO did it all fast and cheap.
Later on, it was picked up by artists and creatives to print zines. To whom it was attractive due to its low cost and lo-fi charm and analogue look.
The ink in the RISO machine is made from the byproducts of rice farming. The machine itself doesn’t have a heating element, which makes it extremely energy efficient.
Both of these aspects make the RISO technique a rather eco-friendly option for your print work.
Because of the stencil-based nature of the RISO printing process, it is well suited to print multiples of the same print.
The cost of the Master sheets would not really make sense to print a single copy of anything.
SO-RI suggests printing posters, flyers, zines and artist editions for the RISO technique to be an affordable and charming way to present your work or advertise your company, organisation or event.
RISO printing is known for its lo-fi charm, so be sure to expect a lot of small and large imperfections. Registration marks will not consistently line up. Smudge marks from handling the paper quite often appear. Roller marks from the machine and ink residue from other inked paper might be visible. Most smudges and ink spots can simply be rubbed away with a rubber gum, just make sure not to rub over any inked areas. Try to avoid large inked areas in your design to avoid a lot of smudges.
If you’re not willing to deal with imperfections and misalignments, RISO printing might not be the thing for you.
SO-RI hosts 18 colours. We have Black, Light Grey, Flat Gold, Burgundy, Purple, Violet, Medium Blue, Blue, Aqua, Teal, Hunter Green, Green, Fluorescent Green, Yellow, Orange, Fluorescent Orange, Bright Red and Fluorescent Pink inks.
Note that these are not your typical CMYK colours and that RISO requires a completely different mindset to work with.
To figure out the workflow of prepping your files for graphical work, illustrations or photography, check out the “file prep” page.
While it’s obvious and easy to look for a CMYK approximate and use Aqua, Fluor. Pink, Yellow and Black for some realistic colours, don’t be afraid to experiment with some different colours.
On the “file prep” page you will find more info on colour separation.
While you might be able to come close to true CMYK colours; exact colour reproductions should never be your goal when using the RISO print technique. Go for bold colours and use the variety of colours to your advantage.
Use these hex codes in your favourite software to approximate the RISO ink colours. Screens can’t reproduce all colours.
Fluorescent Pink | 蛍光ピンク
Bright Red | ブライトレッド
Fluorescent Orange | 蛍光オレンジ
Orange | オレンジ
Yellow | イエロー
Fluorescent Green | 蛍光グリーン
Green | グリーン
Hunter Green | ハンターグリーン
Teal | ティールグリーソ
Aqua | アクア
Blue | ブルー
Medium Blue | ミディアムブルー
Violet | ヴァイオレット
Purple | パープル
Burgundy | バーガンディーレッド
Flat Gold | フラットゴールド
Light Grey | ライトグレー
Black | ブラック
To print a colour, you need a drum. Each colour is stored in its own drum, which is a piece of hardware, which holds an ink tube, a master stencil and eventually imprints an image onto your paper.
Because each drum holds only one colour, and the machine prints with only two drums at a time, printing more than two colours requires you to change out the drums and send the paper through the machine multiple times.
Because the master stencil is stuck to the drum, each additional colour will require a freshly burned stencil.
AM / FM screening
As with silkscreen printing, each colour layer requires a black and white image.
Unlike with screen printing, the RISO can take care of the screening for you. The RISO’s RIP can screen the files in one of two ways (or even combine both at the same time, when we’re including text).
AM screening, or amplitude modulated screening, will use a half-dot screen pattern over your image. In which the size of the dots will change according to the darkness of the image (the darker the image, the larger the dot will become). This is expressed in the RISO driver software in lpi, or lines per inch, which can be variably set from 38 lpi to 300 lpi. For photographs with finer details, it is recommended to only go up to 100 lpi, as any higher lpi will make the image much darker.
The driver software also allows you to set the angle of the half-dot screen, which helps with multi-colour printing.
FM screening, or frequency modulated screening, will spread very fine dots across the image, with the frequency of dots defining darker or lighter areas. The more dots it places, the darker the image gets. This is referred to as grain touch within the RISO’s driver software, but has been referred to outside of the RISO world as diffusion error screening or stochastic screening as well.
The RISO driver will do its best to recognize text and print it as cleanly as possible. It can only do this if the text is seen as text in PDF files. It won’t recognize text in JPG, TIFF or PNG files.
Example of AM screening will follow.
Example of FM screening will follow.