Digital Print

Digital Print is exactly what it sounds like: Printing from a digital source directly onto a type of media.

Digital print will be created using either an Inkjet or a Laser printer. Digital print is more expensive per sheet and also a lot slower than conventional rotary printing which means that it is only really ever used for relatively small print runs.

If rotary printing were used on a small print run then the setting up cost of the machine and of getting the plates created would make the job much more expensive than if digital print was used.

As technology progresses, digital print quality is increasing dramatically and has reached a near perfect quality at large resolutions, making it a suitable 

medium for highly detailed print. As the digital printers develop rapidly we may see digital print making rotary print jobs redundant in the near future.
Digital printers work on a specific set of colours which mix on the page to create the required colour. Unlike rotary print processes, digital print is limited to just these 4 colours. The colours are Cyan, Magenta, Yellow and Key Black.



CMYK


CMYK stands for Cyan, Magenta, Yellow and Key which are the 4 colours that make up every colour in digital print. These colours are effectively blue, pink, yellow and black but with more specific hues.
CMYK is a brilliant way of making a lot of colours because for small jobs it is very cheap and easy in comparison to other printing methods.
The only problem with CMYK is that the gamut is relatively limited compared to all the colours that our eyes can see. Gamut just effectively means a range.
All this means is that there are quite a lot of colours that digital printing can not print.

You can see above that CMYK gamut fills only about a quarter of the visible spectrum. That leaves a lot of colour that can not be printed digitally. 

You can also see the RGB gamut which stand for Red, Green and Blue which are the colours of light that make up colour on screen. Although RGB still cant replicate every colour in the spectrum it is clear that it can make a lot more colours than CMYK can. 

Additive and Subtractive

Additive colour is the process of adding different wavelengths of light (colours of light) together to create new wavelengths. This creates new colours.

This is usually done with RGB colour. When red, green and blue light are mixed they create pure white.

The first additive colour image was created in 1861 by James Clerk Maxwell. He thought he understood how the process worked so he got someone to take a photograph of a tartan ribbon 3 times; Each time with either a red, green or blue filter over the lens. 

He then developed the films and projected each image through a different projector, each projector with the corresponding filter attached and then aligned on a wall. 

When aligned it showed this full colour additive image of the tartan ribbon:

Subtractive Colour

Subtractive colour is basically the opposite. It is the mixing of inks and dyes and paints to make colour and in the case of digital print it means CMYK. Colours are still mixed to create other colours, but in the instance of subtractive colour the light wavelengths are subtracted (or absorbed) instead of added to change the colour. 

The easiest way to differentiate is that additive colour starts with darkness and creates light and subtractive colour starts with light and goes together to make darkness.