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. Spot colour ink is pre-mixed using a set of base colours to ensure consistent 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 differs from process printing, where Cyan, Magenta, Yellow, and Black (CMYK) inks are layered in four passes, one per colour, to create a wide spectrum of colour.

Why would I want to use a spot colour then?

Certain colours don’t reproduce well when printed in CMYK; this is especially noticeable with orange (such as B&Q orange). This is because if they are too bright or vibrant, they tend to come out dull and muddy when printed as process colours.

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 how they're used in the printing process. As mentioned, spot colours are pre-mixed inks applied in a single pass, whereas CMYK inks are layered in four passes to mix the correct colour. This is because CMYK inks are 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 that 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 printing.

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.