What is the workflow for a multi-colour print ?

How do I print a multi-colour print ? What are key points to remember ? What is the workflow ?

KEY NOTES :

  • Think in layers

  • Make sure you change the colour drum when you print another layer

  • Clearly label your files

  • Reminder that registration imperfections happen

Printing multi-colour prints follows the same principles as screenprinting. Each colour represents a layer. So for example, if you are using two colours that means you have two layers to print.

The workflow is similar to a 1-colour print except it introduces the concepts of colour separation and registration into your workflow

  1. DESIGN » File setup of colour separation

  2. EXPORT

  3. DRY

  4. ASSEMBLE

  5. PRINT 2nd LAYER » Registration

*refer to one colour print for details of each step*

COLOUR SEPARATION

Risa doesn't read in colour, it only reads the saturation (intensity of colours).

Prism + Light = Colours

WHAT DOES THAT MEAN ?

Well, you may have seen an image of a light shining on a prism and on the other side shine the colours of the rainbow. This little science experiment exists to prove that light contains all the colours.

But what this also proves is that without light there is no colour. For example, a red table set in a dark room, in our eyes will look dark red, if it's really really dark, it will look black! But the same table set in a well lit room is bright red.

Dark Room
Well-lit Room

Going back to Risa, the machine can't actually understand or see colours this way because it doesn't use light. Instead, it reads saturation (intensity) and prints whatever colour ink is in the machine. Because of this, we have to convert our images into greyscale.

EXAMPLE:

You make your design ! Wow c'est beau ca

final design

1.) Separate your design into colours. Make sure to clearly label them.

Calques Fênetres
black couche
jaune couche
bleu couche

2. Then you have to convert each layer in greyscale.

*Keep in mind what colours looks like in greyscale. For example, yellow simply converted into grey will print a lighter version of yellow with the Risograph. If you are wanting 100% yellow in your design, you must convert the parts that are 100% to be 100% black.

3. Export each layer, clearly labelling them

CHECKLIST:

  • Organize your layers

  • Properly name layers

  • Properly convert your colours

  • Properly export each file ex. TCC_chart_bluelayer; TCC_chart_yellowlayer; TCC_chart_blacklayer

  • Export in PDF

  • Export 300 dpi

REGISTRATION

Registration means lining up each layer so it prints the design you created.

With the Risograph, you register using these machine buttons :

Registration is not always perfect so this is why it's important to print extra copies of your design as registration tester prints.

Notice how the layers are a bit mis-aligned
Notice how the layers are more aligned

PRINTING

Your design will dictate the order you print layers. The general rule of thumb is to print from lightest colour » darkest or to print from largest blocks of colour » more detail