Inks are transparent so allow for a build up, creating a different colour when printed. The lightest colour is printed first - Yellow. The layers build a full colour image from their individual tints.
Part 1: Using Illustrator with CMYK Colour:
CMYK is also referred to as a process colour, and which refers to the colours that are being printed with.
CMYK or RGB can be selected for the colour mode, however CMYK is always the default when using Adobe Illustrator.
Colour can be applied using the colour picker tool when double clicking over the colours selected shown to the above right.
The colour guide on the top right of illustrator can be used to choose colour, or even the swatch palette. (Shown below):
If the swatch palette is used the same colour can be used consistently though design or art work, as you can make your own swatch for a certain colour using the CMYK percentages. Or when objects are selected to the coloured, using the swatch palette ensures correct colour use and simplicity. The images below shown the swatch selected for a colour change, and the relevant CMYK code which can be used to create a new swatch if desired.
In the swatch palette, any colours which aren't needed can be deleted using the 'trash can' icon at the bottom of the palette.
This can be done faster by using the 'select all unused' in the swatch options palette. This leaves the ones being used only, which can be seen on the right.
Swatches can be displayed differently also by changing the layout of the swatch palette.
The registration swatch, is used for crop marks and printer marks etc. It isn't shown on the layout but is added when printed.
From here we can build our own swatch library with appropriate colours. This is done by selecting 'new swatch' which then leaves options to change the swatch name, colour type and colour mode, as well as percentages for CMYK colours. Ink percentages can be mixed, and then the swatch name will automatically change to the relevant percentages that make up the colour swatch.
A shade of purple has been created by altering the percentages for Cyan and Magenta.
Colours can also be made using the colour picker tool. This is shown below.
It is also possible to edit a swatch once it has been created on the swatch palette.
Different colours can be applied using the colour picker. And then each colour can be easily added to the swatch palette for further use. This is done by dragging the colour picker sample to the swatch palette. Or the colour palette can be used, then clicking the link 'create new swatch'.
'Create New Swatch'
Or if several colours needed to be applied to the swatch palette for another piece of design for example, and you select 'add used colours' they will add themselves to the swatch palette.
Swatches added in this way will have a triangle in the corner. This means that when the swatch options are open, the 'global' option is ticked. This means that every object which is using this colour, will automatically adjust in colour when it is changed or altered. Allows for 'global changes'. Any swatch can be a global swatch by ticking this box.
Both the colour picker and the swatches can be viewed at the same time.
When a colour is selected on an object, the colour picker changes to tints (colour + white) allowing variations to be produced/changed. New swatches can then be added from here also. Allows for organisation within a small colour palette, or a palette with various tints or shades.
When using tints, colour can be changed globally also, and by altering C, M, Y or K within the colour specific details.
For example, Cyan has been changed here below:
Applying and Printing with Spot Colours:
Spot Colour is a solid colour, and not made up of the CMYK printing process. Each spot colour has its own ink.
Using spot colours to print can make it significantly cheaper, as there is only one colour being used. Where as with CMYK, there are 4 inks, requiring 4 printing plates, etc.
If cost is an issue, or two colours are being used for a print job, using spot colours are much cheaper to print with.
Where as, if CMYK is being used plus 2 Spot Colours, then this will make the print job more expensive due to 6 inks being used.
Spot colours are also used for consistency within reproduction for brands and logos etc, for example, Coca-Cola Red or Sainsbury's orange.
Some clients, or corporate companies, will give you a specific pantone colour/code to print with which is specific to them.
Metallic and Fluorescent spot colours are also available. These are specialised inks.
Spot Colour libraries are often called colour books, such as the PMS, Pantone Matching System.
PMS is available for coated and uncoated stock, metallic inks, pastels, fluorescent. Each colour chip has a unique reference number.
The number would be referenced, and when sent for digital print, the printer has the code for the pigments and binder to be mixed together.
All of these reference numbers are available in Illustrator. These can be accessed via the swatch panel.
Under colour libraries, all of the colour books and Pantone matching systems are all listed online to allow easy commercial printing.
If a reference number is known, this can be searched for and colours can be selected quickly and easily without searching through the entire Pantone Library. Each colour to be used needs to be added to the swatch palette being used, by clicking on the colour desired in the PMS library. These can then be seen in the swatch palette below.
This colour system only works within commercial print, and NOT with laser printing or ink-jet printing etc. If you use a spot colour, the printers will usually print a copy to approve of the colours being printed. The reference colour is usually accurate when printed to on the colour chips.
The pantone swatches above show differently in the swatch panel above. It has a cut corner, showing it is a global colour, with a 'dot' as a spot colour. This is differently to the CMYK colours added manually.
Tints can also be set up of this spot colour chosen, to allow for tonal variations of the colour.
Below are three tones of the Pantone 992 C. They are all printed with the same colour ink, with more space between the printed dots allowing for a lighter shade (same principle as screen printing dots). This is called half toning.
The three tonal shades have been blended to show more of a gradient view of the tones for an idea when printing.
Swatch libraries which have been created can be saved to be used for the same design work again for example.
'Save Swatch Library as AI' and then save into Swatches folder, which should automatically come up when being saved.
When saving a palette for another piece of Adobe software, then save as an ASE. Can be used on Photoshop or InDesign. This file should be saved in the same project file as design work to find it easily when opening in Photoshop, for example. This will not transfer tints and shades, but will accept spot and CMYK colours.