All about colour

Spot Colours

For centuries we have been adding dyes and pigments to liquids to make inks. By mixing various natural and man made pigments we are able to make a huge number of different colours, and by knowing exactly what was mixed in what proportions the colour achieved can be matched exactly time and time again.

So that they can be matched across the world colours are referred to by what is termed a pantone reference. If you know the pantone reference we know the recipe to be used to make it up. (If you don’t know the pantone reference of your colour you can send us a sample to match and we can determine the reference and hence the recipe. As good practice it is always good to let us have a sample to make sure that what you have been using is actually the pantone that you think it is!) 

If your printing requires one colour, sometimes called one spot colour, and we know the pantone reference, we will be able to match it exactly. Similarly if your printing requires 2 or more colours, with the pantone references we will be able to match exactly by buying or mixing the relevant inks and printing 2, 3 or more spot colours.

It should be remembered that ink is translucent- you can see through it. Therefore if you put the same ink on different coloured paper, the colour of the image will vary. The same logo on white business cards and cream letterhead will look different.

There is also a difference in how the ink reacts with different papers. Some papers have a coating applied to give a really smooth often shiny finish. These are called coated papers. Those with no coating, unsurprisingly, are called uncoated.

An ink applied to a coated paper will tend to sit on top of the paper while it will tend to soak into an uncoated one. The same ink will be a slightly different colour on the different types of paper. Pantone references of colours therefore have either a c or a u at the end, relating to whether the recipe will create an ink that will produce that colour on either coated or uncoated paper respectively.

Again it is likely that a business card board is going to be coated and letterhead paper uncoated. Even using pantone referencing, applying the same ink to both may produce a slight colour variation.

Tints

At its simplest a coloured ink is applied solidly all over the area to be coloured. However, even using just one colour, variation can be introduced by creating tints. Here rather than applying the ink as a solid, the area to be printed is broken down into microscopic dots. Although the ink is being applied as dots, because they are so small the eye is deceived into seeing them as a tint of the base colour. The smaller the relative size of the dot the lighter the tint will appear. So from simply a single colour a whole range of effects can be achieved.

Therefore, to correctly specify an exact colour you need to know both the base pantone reference and the % tint.

Full Colour Process Printing

Full colour process (sometimes referred to as Four Colour Process or CMYK) is a print method that allows the reproduction of an almost infinite variety of colours and shades on a single sheet of paper by simply applying 4 colours of ink, Cyan (a blue), Magenta (a red), Yellow and Black (hence CMYK). The 4 inks are applied as dots like tints and the relative proportions of the 4 colours within one very small area of the page trick the viewer into seeing it as a distinct colour. Images with graduations of colour, brightness and tone, such as photographs are therefore printed in four colour process.

Because we are able to print an almost inexhaustible number of colours using Four Colour Process printing we can print a number of different coloured items either at the same time or one after the other on the same press without all of the time and chemical expense involved in washing the press down to change the colour ink it is using. This is why full colour process printing is cheaper than printing four spot colours where the press would have to be cleaned before and after the job.

Most pantone colours can be reproduced almost exactly using four colour process printing. Strangely however there are a few colours that can be made by mixing inks in a tin but can not be reproduced using this type of printing. Even where the match is good, by the nature of the process it will not be exact.

Which is right for me?

At Simply Letterheads we have a mix of one, two and five colour presses so we can use the most economical press for the job, which is reflected in our prices.

If your print job is only 1 or 2 colours it will be most economical to print it in 1 or 2 spot colours. You will get an exact colour match and it can be done on the smaller, cheaper 1 and 2 colour presses.

If your job requires 3 or more colours it will have to be printed on one of our 5 colour presses. If exact colour match is vital, especially if you use one of those pesky colours that don’t really match in full colour process, it should be done in however many spot colours are needed. If all of your colours translate well into full colour process, or if exact colour match is not so important, it can be printed this way with the associated cost saving coming from the reduced costs in relation to washing up discussed above.