Risograph printing is a spot colour print method based on layers.
Similar to screenprinting, the Risograph uses single colors to print designs from a master stencil. Riso sits between screen printing and offset . Using a stencil-based printing process and vegetable based inks gives riso-prints a result similar to silkscreen with vibrant bright colors. The prints themselves have a very distinct tactile quality that is impossible to duplicate on an inkjet or laser printer. Great for art prints, posters, and pretty much anything with a graphic quality.
The file is sent from a computer to the machine. A master is created for each color by burning a negative image onto a waxed sheet. This master is then wrapped around a drum and ink is forced through the voids of the master. The paper runs flat through the machine while the drum rotates at high speed to transfer each image on the paper.
Designing an image for printing on the Riso is quite a bit different than designing for other types of printing. The key difference is that with the Riso you can only print two spot color at a time meaning your range of colors on each print will be limited. Depending on the ink coverage, we often recommend a maximum of 5 colours. You will also need to account for how your color layers will be halftoned and layered in the final print to achieve your desired outcome. After you have a proof in hand any changes you would like to make to the design will require new masters and test prints.
The most simple way to prepare a design for Riso printing is to create a separate grayscale image for each color layer you intend to print. This can be done either in Photoshop, Illustrator, or by hand to be scanned. These grayscale images can then be burned as a master on any color drum of your choice.
100% black in each color layer, will print out as 100% of whichever color you are printing. 90% black will print as 90% and so on.
* For color separations and more detailed information on how to prepare the files please find attached more links at the bottom of the page
Source images should always be delivered in grayscale format at 300dpi. From lines at 100% to gradients and elements at different opacities. For best sharpness, text should be set in vector format. We recommend a minimum of 5 pt.
Try to avoid large areas of ink at 100% opacity to avoid roller marks and ink inconsistency in your prints.
When preparing the files you should also take into account their names. Each colour with a pdf file + a colour preview file
Paper and Format
We can can print 2 colors in one pass on A3 and smaller size paper.
Risograph printers can’t print full bleed A3 and can only print on uncoated papers. There is a small margin which is about 5mm making up the non printable area. The safest option is to leave 10mm on the long and short side.
Riso can print on papers between 60-300 g/m². Usually the thickness limit we suggest is 250g/m² because 300g at times can be tricky and might require proof of you artwork before we print.
We usually keep in stock between 5 to 10 types of papers. If you have a larger print run on a particular type of paper that we do not have in stock, please allow 1-2 weeks for ordering and delivery.
You are welcome to bring your own paper, as long as it is technically suitable for printing.