CMYK or Pantone:
when a spot colour is needed.

Two ways of reproducing colour

Offset printing reproduces colour in two ways. In four-colour process (CMYK), cyan, magenta, yellow and black inks are printed as halftone dots that combine visually to form every shade in the job. With a spot colour, the shade comes from a single pre-mixed ink, printed from its own plate and specified by a reference from a colour-matching system, most commonly Pantone.

The choice is not a matter of taste. It determines how accurately a shade is matched, how consistent it stays between reprints and what the job costs.

When a spot colour is needed

• Brand colours. When the shade of a logo has to be identical on every printed item, on every substrate and at every reprint.
• Shades outside the process gamut. Vivid oranges, bright greens, deep blues, metallics and fluorescents cannot be matched faithfully in CMYK.
• Large solid areas. A single ink printed as a solid gives a more even result than a build of four.
• Fine detail in colour. Small type and thin rules print more cleanly in one ink, with no register between colours to hold.
• One- and two-colour work. Where there is no photographic content, one or two spot colours are often the sounder choice.

When process colour is enough

Jobs with photographs, gradients and many different colours are printed in four-colour process. The same applies when the required shade can be achieved in CMYK within an acceptable tolerance. Many jobs combine the two: process colour for the images and one spot colour for the logo.

Points to bear in mind

• Conversion is an approximation. How closely a Pantone reference can be simulated in CMYK varies from shade to shade. Some match almost exactly; others shift visibly.
• Paper changes the result. The same ink looks different on coated and uncoated stock, which is why colour guides are published separately for each.
• The screen is not a reference. The valid reference is a printed colour guide or a contract proof.
• Each spot colour is an extra plate. It affects both cost and production scheduling, so it is best decided at the outset.

In the artwork

A spot colour is defined in the file as a spot swatch, under its exact name and under one name only throughout the document. Anything that will not be printed as a spot colour is converted to CMYK before the file is supplied. Full guidance is given in our file specifications.

Our approach

At Terzidis Print every file is checked before it goes into production. Where a shade is critical, we recommend the method of reproduction that suits the job, and colour is measured throughout the run so that it stays consistent from the first sheet to the last.