Printing – Under the Magnifying Glass

Printing under the magnifying glass

Have you ever wondered how standard printing manages to replicate so many colours from so few actual inks? With just 4 inks at play (cyan, magenta, yellow and black), it’s staggering when you think about it –  a whole rainbow and more can be rendered while, at the same time, the palest of pale hues are possible despite the original 4 individual inks used in the machine being, on their own, quite punchy and saturated.

Tints

The secret is the use of tiny spaced out dots, called ‘tints’. So, for example, the ‘sky blue’ ink called cyan can be printed as anything from a grid of tiny spaced dots to a full solid. The solid will obviously still look like sky blue but the smallest spaced dots at the other end of the scale will end up looking, to the naked eye, like a very pale blue. The printing trade grades these tints as percentages (i.e. a percentage of how ‘solid’ they are) where 100% is solid cyan and 1% is the palest of pale tints.

Tints of process cyan

Mixes

This process is taken a stage further by overlapping the tints or solids of each of the 4 ‘process’ colours as they’re also known. So a solid magenta (rich pink) overlapping a solid process yellow will result in a primary red being visible to the onlooker. 50% tints of each of those will result in a mid pink, 10% tints of each resulting in a very pale pink and so on. Similarly process yellow overlapped with process cyan will result in various shades of green, depending on the tint value used. It is this type of overlapping of tints, mixed to a much more complex level, which allows the 4 colours to mimic full colour photographs like you see in magazines and in printed brochures.

Photo close-up showing printed dot formation

Black is just black – isn’t it?

Black is just black right? Well, yes and no. Yes, you could print black using a solid of only the ‘process black’ ink and you’d get a black print-out for sure. But actually, you can get a much more dense black by printing the solid black over tints of one or more of the other process colours. So, for example, printers often print solid (100%) black over a 40% tint of cyan so as to give the black a ‘boost’. With such an approach the resulting black will be darker and more dense. You can also make the black even more dense and saturated if you print it over a (usually equal) tint of ALL the other process colours, however it could be argued that on particularly long print runs this can increase the price of the job simply because of the shear amount of extra ink being used up. However this is not an issue on lower print runs as the extra ink is then negligible in quantity.

You can also give the blacks a subtle hue; for instance 100% black printed over 40% cyan makes the black look slightly ‘cool’ whereas if the cyan were substituted for magenta then the resulting black would have a slightly ‘warm’ feel about it … but the differences are only subtle.

It is also worth noting that very dense solid blacks often also require a final ‘sealant’ or ‘varnish’ of some kind because, without one, the solid black area can fingerprint quite obviously when handled, particularly on ‘coated’ paper. A sealant or varnish is not required, of course, if the final job is to be laminated (gloss and matt lamination options are available).

Other Dot Formations

It should be noted that the above article relates pretty much always to litho printing. The same rules also apply to most (but not all) types of digital printing, including the type used at Firstpoint Print. However a small exception with some forms of printing, including most inkjet and some large format printing processes, is the use of ‘random’ dots i.e. instead of a regular ‘grid’ of dots being employed for any tints, they have a random pattern when viewed in close-up. This simply makes any dot ‘formation’ less obvious under very close scrutiny. Indeed photographs printed using a random dot formation can look closer to photographic quality or ‘continuous tone’ as a dotless print-out is sometimes known.

Litho, Digital and Large Format printing services for London

At Firstpoint Print we can cater for all your printing needs, whether that’s litho or digital for printed literature, brochures and stationery or large format for display material like posters and exhibition panels. All our printing and finishing is done in-house so our prices are very competitive and we have control over every aspect of every job, hence quality is always first class. With branches in Clerkenwell, London Bridge and Victoria we are sure to have a branch for convenient to any part of London. See the contact page here or request a printing quotation online, here.