CMYK vs RGB vs Spot Colour
CMYK and RGB refer to the two main 'colour spaces'. RGB represents Red, Green and Blue, the three colours used to make up light, such as on your TV screen or computer monitor. CMYK on the other hand stands for Cyan, Yellow, Magenta and Black, and these are the colours used to make up full colour print. Incidentally, the K is used for black (standing for 'Key') as B has already been used for blue. All this is confusing enough already without the same letter representing two different colours!
Why are different colours used for light and for print? Well, in simple terms, when using RGB the zero setting (i.e., if there is zero red, zero green and zero blue) gives you black. The more of each colour you add, the closer you get to white. With CMYK, you start with white (as in a blank piece of paper), and the more colours you add the closer you get to black.
Quite annoyingly, the colours that RGB can create with are different to the colours CMYK inks can produce. Therefore, it’s always better to design in CMYK if you can. If you design in CMYK, the printed version of your design will look much closer to your screen version than if you design in RGB. We can print from RGB files, but we wouldn’t want you to be disappointed with the colours when it’s printed and they don’t look how you expected them to. CMYK printing is also known as full process colour. This diagram gives a rough idea of the different colours that can be represented.
One of our most common colour problems is when standard blue is used in Microsoft Word. The bright blue you see on screen cannot be printed using CMYK and will come out darker.
You may have heard of spot colours or even have a specific colour code that you want printing. The most well known spot colours are the Pantone system. They give you a choice of over 1000 specific colours to print in which will always print exactly the same. If it is crucial that your colours are always perfectly consistent from one print run to the next, you should use spot colours. CMYK printing is normally pretty consistent, but there can be slight variations from one run to the next, and precise colour matching is not possible.
Whilst we can print using spot colours, it has a number of disadvantages. Firstly, it limits what you can print. Photographs are normally printed using full process colour. If we are using spot colours, we can only make up images using the spot colours being printed with.
In addition, because the vast majority of printing we do is CMYK (full process colour), we can batch print jobs. That is to say, we can print several different leaflets on our large press at once, splitting the set up costs between a few customers. If you are using spot colours, we will have to set the press up specifically for your job, so the set up costs can't be spread.
Make sense? So far, we’ve got the format, the picture resolution and the colours. On to a winner right here. Let’s break it up with a quick tip…
OK. Laying up designs next.