What’s the difference between spot colour and CMYK?

Have you ever had some artwork created only to be asked by your print supplier to supply it as a ‘spot’ or ‘special’ colour and wondered what it meant? 

Well, don’t worry because in this blog I will do my best to explain what this means.

So what is a spot colour?

A ‘spot’ colour, ‘special’ colour or ‘Pantone’ colour is simply a solid colour. The spot colour ink is pre-mixed using a set of base colours to ensure consistency in colour reproduction. It can also include specialist inks such as metallics, fluorescents and clear varnishes.

Okay, so what is spot colour printing?

Spot colour printing is where individual colours are printed using a plate in a single pass. This is different from process printing, where Cyan, Magenta, Yellow and Black (CMYK) inks are layered on four passes, one per colour, to create a vast spectrum of colour.

Why would I want to use a spot colour then?

Certain colours do not reproduce too well when printed CMYK, this is particularly noticeable when using orange (such as B&Q orange). This is because if they are too bright or vibrant they tend to come out dull and muddy if they are not printed as a spot colour.

If you specify a certain spot colour, you have a much higher chance of getting a consistent tone across all of your printed material as spot colours are often catalogued in a system, such as the Pantone Matching System.

What is the difference between spot colours and CMYK colours?

The main difference is in their use in the printing process. As mentioned, spot colours are pre-mixed inks that are applied in a single pass whereas CMYK inks are layered on four passes to mix the correct colour. This is due to CMYK inks being transparent so they interact with each other. Spot colour inks, however, are opaque and won't interact.

Spot colours are used almost universally. The Pantone Matching System (PMS) spot colours are used across Europe and the USA. This means whether a job is printed in Europe or the USA, the output will contain the same colour. Also, if you have a Pantone book, you can see an accurate representation of the colour before going to print.

What are the benefits of spot colours?

Spot colours provide an exact match and are therefore a great choice when you want perfect colour reproduction across different materials and substrates.

Now you know the difference, but if you need any more information, feel free to contact me.