What is a CMYK process?

Large format print machines whether they be solvent, UV, Latex or Dye sublimation all use a CMYK Printing process. The name CMYK refers to the colours, Cyan, Magenta, Yellow, and Black. Some sources say the K refers to the last letter of Black as not to confuse with blue as blue is used in other print techniques, but this isn’t the case. The actual reason is that the letter K refers to Black and means ‘Key’. ‘Key’ refers to a lithographic printing term. Black is often used as an outline and printed first. The black plate is called the ‘Key’ plate with the other colours lining up to the Black is referred to as ‘K.’

Digital Piezo print heads produce small dots of Cyan, Magenta, Yellow and Black to create a wide range of colours. Digital printing is ideal for printing one-off artworks on large format printers without the need of making print plates which incur expensive setup costs. When overlayed, these coloured dots produce a four colour image. Some modern printheads can create larger and smaller dots, thus providing a higher definition print. Varying the dot size gives greater clarity and definition to halftones and lighter print areas.

What is a Pantone colour?

A Pantone® colour is a colour reference from a Pantone® chart. Pantone® is a trading name, and Pantone® is the printer industry-standard go-to colour guide for the print and graphics industry. Pantone® provides colour booklets with solid colours which can be used to match colours on printers. The booklet is in simple terms a colour communication tool between print houses and graphic artists.

Because the chart is a physical printed booklet, each print house refers to a Pantone® booklet for reference. Merely by quoting a colour reference from the book, another print house can look up the colour and use this reference to the make the best possible match. The print operator can then can adjust the CMYK colour setting to replicate the colour as closely as possible. The Pantone® matching systems do have limitations which we will discuss in these next sections.

Around 85% of Pantone & Spot colours are achievable using a four colour CMYK process, but brighter colours are sometimes unachievable.

The CMYK print process allows us to print a vast array of colours, quickly and cost-efficiently.

Pantone® colours do, however, have drawbacks and limitations and it is not always possible to replicate all Spot or Pantone® colours

 In the next sections, we will explain the different colour terminology, which will give you a better understanding of the Pantone® limitations.

Can we match Pantone colours?

We can Pantone match specific Pantone® colours but cannot guarantee an exact match. We will endeavour to match as close as possible to your chosen colour using the CMYK Process. Some Pantone colours are impossible to match due to colour gamut restrictions.

What is a Spot colour?

Each colour in a Pantone® chart is a ‘Spot Colour’

Spot colour refers to a colour where the ink has been mixed from a mixture of pigments. The mix of pigments creates a solid spot colour.  

The best way to explain this is by mixing the different colour of paint to make a new colour, thus creating a new colour or a ‘Spot Colour’.

What is a Process Colour?

A process colour is a colour that is made of dots of ink using a group of limited colours. Unlike Spot Colour, a Process Colour uses a variety of mixed dots of ink to create a new colour. Process Colours have limitations. Process colours can only be produced from a mix of dots of predefined colours. As we work in a CMYK format for this instance, we will refer to this as a four colour process. The four colours as discussed earlier are Cyan, Magenta, Yellow and Black pigments. Because of the limitation of only four base colours, specific colours and bright colours are impossible to match fully. The limitation is due to limitations of the colour gamut. Having only four base colours to start means no other pigments can be introduced into the process, meaning the colour gamut is limited only to the original pigments. Colours that would be impossible to match using a four colour process would be super bright and vivid in colour. Here are is a list of colours which would pose potential problems:

  • Bright Oranges
  • Lime greens
  • Vivid blues
  • Deep indigos
  • Fluorescent colours
  • Metallic colours

Pantone matching is a time-consuming process. If you require Colour matching, please inform us before ordering. Colour matching will incur an extra fee of £30+vat per colour.

Other colours that are problematic to match are greys and creams. Grey, in particular, is a questionable colour. When printing grey or cream, it is always safer to quote a Pantone® reference.

Grey is a shade and can be produced from a mix of all the CMYK base colours. All colours can be present in a grey colour, not just Black. The reason that grey is so tricky to match is as follows:

A touch of Cyan removed – 1-2% could have a massive impact on the colour hue of the grey and make it much colder in shade.

The same effect will happen if print software translates the grey slightly warmer and adds slightly more Magenta (redder) to the colour mix. The result could be an overly warmer grey.

Can you print metallics?

It isn’t possible to produce metallics using a four colour process. We only print from a CMYK mixture of colours. Metallic colours may only be produced from a specially formulated metallic spot colour.

Author Profile:

johnny

John has over 22 years of experience in the signs and graphics sector. John began his career in signage in 1998 after leaving college where he gained a National Diploma in graphic design. John has a wealth of all-round expertise and knowledge and has worked in many roles within the signage industry. As well as being an experienced graphic designer, John is an experienced sign manufacturer and vehicle wrap installer.