Risograph GR3750

This page describes the Risograph GR3750 copy-printer available at the Community Print Resource in Nottingham (also see [1] and [2]), which is run on a self-service basis.

The Risgraph GR3750

The Risograph looks like a photocopier, but it operates in two stages:

1. it scans the source document to create a 'master' on a piece of disposable plastic; then
2. it prints a run of paper copies using a single colour.

To print in multiple colours this process must be repeated with different inks.

Design issues

Only four colours are available (red, green, blue and black) and the Risograph is not well suited to printing large blocks of solid colour. It is not possible to line-up multiple different colours accurately, so multicolour designs should allow for a little misalignment, and pages also require a small border (10mm is recommended). Despite this, the Risograph can produce very cheap stylish prints if you create suitable designs.

Pricing

This printer is run at cost price for community groups (including Nottingham Hackspace). When we use our own salvaged paper, the cost of single-colour printing is just 1p per side, plus £1 for each master.

Paper

The Risograph accepts paper in the standard sizes A3, A4, A5 and A6. The paper weight can be 46-210 g/m², which includes everything except card and very light paper. The maximum printable area is 290x412mm.

Installing ink

The ink cartridges are large and need to be lifted into the machine one colour at a time.

A new ink cartridge about to be loaded.

The blue ink cartridge.

Loading the green ink cartridge.

Loading paper

Paper should be loaded into the tray on the left side of the Risograph. The paper should be face-up (the Risograph will print on the top side of the paper).

The paper tray.

Making a master

Select a mode (line, photo or duo):

• Line mode is suitable for plain text and single-colour line art.
• Duo mode will print shades of colour and preserves the sharpness of line edges.

Each time you make a new master, the Risograph will use another plastic sheet and will destroy the previous one. The used master sheets are collected in the tray on the left side of the machine.

The tray of used master sheets.

A used master.

Printing a run

After you have made a master, the first few pages in a print run will not come out at full strength and may be patchy.

The first few pages of a print run.

An initial print.

A later print in the same run.

Adjusting the contrast

There are two contrast settings you can adjust:

1. the contrast used when making the master; and
2. the amount of ink applied when printing.

The buttons below this display are used to adjust the contrast.