Question 1

What is a Risograph?

Accepted Answer

A Risograph is a japanese spot color duplicator that was designed and manufactured by Riso Kagaku Co. in 1986. 
In simpler terms, its a screen printer inside of a copy machine.
Inside the machine, it burns a Master (paper screen/stencil) of your image and wraps it around a single color drum. The paper is fed into the machine, wraps around the drum and as the drum turns, it releases ink throught he master and onto the paper. The paper is then released and carried out the other side. All happening at warp speed. 
Risographs can be very high speed printers, usually printing around 150 pages per minute.
 
Riso's use soy based ink which "dries" by being absorbed into the paper. Just like offset printing (newspapers!) Only uncoated paper stock please! 
 
Beacuse of their one color at a time printing method (though some larger Riso's can do two), this allows for both inexpensive and fast one color printing.
Layering colors (making multiple passes through the machine with different colors) has been a tried and true printing method from screen printing to block printing, lithography, and Intaglio.

Question 2

Color Seperations?

Accepted Answer

What are they?! 
They're cool and what allows you you print more than one color on a Risograph!
 
A normal full color image consists usually of RGB, or CMYK.
RGB: is Red, Green Blue and are the colors of the teeny tiny LEDs in screens. (The one your looking at right now.) 
CMYK: is Cyan, Magenta, Yellow, (K) Black. (K stands for Keyplate. A fancy medieval term from letterpress printers back in Gutenburgs time.) These colors are found when you are shopping for expensive ink cartridges for your home desktop inkjet that always seems to need ink. These are the colors used most commonly in printing. Even though Risographs don't always specifically use these colors (thats a fun benefit!) We still use this to color seperate.
 
Before a Risograph can print your file, you need to have your colors seperated. 
Riso's read every file in greyscale. (Bassically they are color blind, so we gotta do the work for em.) For a full color image, regardless of the colors you are using, each color needs to be its own seperate file.
For example: My illustration has red, blue and pink. 
File 1: everything in my file that is pink
File 2: everything in my file that is blue
File 3: everything in my file that is red
Then we send put the pink drum in the Riso, and print the pink file. 
Same for each color after that. 
 
Whats fun is layering colors over each other and printing them on top of each other to make a totally new color without using that color ink. 
Have a file that has Red, yellow and orange? That only needs two colors because layering the yellow and red over each other will make the orange. No need a seperate file for that. :)

Question 3

Why would I want to Riso print?

Accepted Answer

I don't know, you tell me! 
I can give you some ideas though.
 
1. Its very cost effective, fast, and eviromentally friendly.
2. You can print colors you can't normally on a regular digital printer. (ie. Flouresents, white, gold, etc.)
3. You are supporting an indenpendant artist, not a huge corperation.
4. You can get the unique screen printed, offset comic book look without getting your hands dirty. (well I do a little, but YOU don't have to. :) )

Question 4

What size can I print?

Accepted Answer

My Risograph SF5130 has a print area of 8.5x14. But it can print on paper up to 11x17.
Need more info on this? Message me!

Question 5

What can I print on?

Accepted Answer

If you looked at the FAQs above this, you'll know that Risograph's use Soy based Ink. 
This ink only dries through absorbing into the paper. So that paper needs to be uncoated to let the ink seep into the fibers.
Glossy, semi gloss, some mattes, etc. has a clear plastic film coating the paper that doesn't let in the ink, instead it sits on top. Think of water on a plastic bag, it wipes right off. Your ink will too on coated stock and it makes a mess.
This is ideal for Lazer printers that use heat to cure the ink onto this stock without needing to absorb. Riso's are not this way.
 
In short, UNCOATED STOCK ONLY PLEASE!

F.A.Q.

Frequently asked questions

What is a Risograph?

Color Seperations?

Why would I want to Riso print?

What size can I print?

What can I print on?