RISO works by transforming your black and white artwork in a paper stencil, which is called a master.
For each colour of your artwork, you need a new master, they are not reusable. Once you have chosen the colour/s for your artwork, you scan or upload your image in a file to the machine.
The chosen colour drum is inserted into the RISO and the paper stencil with your artwork is wrapped around it. Each drum is assigned to one specific colour. Once in the machine, the ink from the drum
is pressed out through the stencil onto the paper, while the drum is rotating at high speed.
Paper is fed flat through the RISO. The colour drum rotates inside, “kissing” each sheet of paper that passes under it, printing the image. Each print comes out slightly different, due to the ink coverage, texture of the drum, slight movement of paper while passing under the drum.
One colour is printed at a time, for each colour you need to switch the drum and pass the paper again through the machine. When printing a multicoloured artwork, you are repeating the process to compose your image.