The Printing Process
RGB and CMYK
During the printing process, there are two ways to represent colour. First, there’s R (Red) G (Green) B (Blue), which is used to create colours on screens. It is an additive colour model, which means that it adds those three sources (lights in this case) to make pretty much every single shade imaginable, with white being the colour you get when you add the maximum amount (255) of each colour. In relation to printing, it’s used to preview what’s going to be put on the page, however sometimes the colours can be off, so a sample copy (a proof) should always be consulted before large amounts are made. For the actual physical act of impressing colour onto pages, the C (Cyan) M (Magenta) Y (Yellow) K (Black) system exists. It is a subtractive colour model, which means that you are taking away white by colouring in the paper.
The image that’s being printed is encoded in a way that a printer doesn’t understand. A Raster Image Processor is a piece of software that remedies this by translating the underlying code into a format that it does understand. After this, the picture is seperated into the four base CMYK colours, and each seperation is applied extremely precisely on to the paper in the precise concentration needed to create the mix of colours necessary, the spectrum of which can extend far beyond cyan, magenta, yellow and black. The proof, as I have said, is closely compared to the copies being made to ensure consistent precision.
The main forms of printing, and their common uses, are as follows:
Offset Lithography – Stationary, brochures, newsprint, booklets
Screen Printing – Printing onto fabrics, glass, and generally non-conventional surfaces
Flexography – Food and pharmaceutical packaging
Digital Printing – Short-run and once-off prints
There are a number of finishes that can be applied to finished products of this process, such as guillotining (physical cropping), laminating, folding and embossing, and many more.
In order to supplement this learning outcome, I decided to see how much it would cost to print 1000 double-sided, full colour business cards around Dublin. Here are the results of this small endeavour:
Printer Quoted Price