Spot colour printing refers to the use of inks which are physically mixed to the right colour in liquid form, before being used on the printing press. So, for example, the spot colour ‘Pantone 328C’ can be printed in a single pass of the printing press, using a single printing plate. This is in contrast to printing a similar colour, although not as accurately, by overlapping the tiny dots of the four ‘process’ colours of Cyan (‘C’), Magenta (‘M’), Yellow (‘Y’) and Black (‘K’), otherwise known as “CMYK” and “four colour process” printing. That, of course, necessitates 4 passes of the press, using four printing plates instead of just one. More information about ‘process’ printing can be found in our previous blog post but, for this article, we will concentrate on only spot colour, its uses and benefits.
So why use spot colour?
In essence, using spot colours will generally give you the very best match possible to the exact colour you have in mind. While ‘process’ (CMYK) colours can get a pretty decent match, spot colours can get an exact match. Spot colours are also the only way to print colours such as metallic inks, some pastels, super-saturated and particularly bright colours like fluorescents and even some colours that you might think were fairly standard, for example some blues, which can be troublesome using CMYK. Also it’s worth bearing in mind that if you are printing a 2 colour job, you can literally print it using 2 spot colour inks (with 2 plates and 2 passes of the press) whereas with ‘process’ printing you’d need 4 of each. (This matters less with Firstpoint Print’s digital printing process, because it is a plateless process, but it potentially makes a significant difference to pricing and colour accuracy on their litho printing presses).
To illustrate the difference in colour accuracy using ‘spot’ vs. ‘process’ printing, here are a few examples showing a representation of the same Pantone colours using both colour models (N.B. slightly exaggerated for illustrative purposes). On the left is the ‘spot’ colour version where the ink is pre-mixed before going onto the printing press. On the right is the same Pantone colour generated using the ‘four colour process’ (CMYK) model. You can see that there is quite a difference for the particular Pantone colours we’ve selected, with the spot colours being more saturated and bright, while the CMYK equivalents tending to be a little less so.
We should point out that the difference is less pronounced for many other colours in the Pantone range.
Metallic inks simply have to be produced using spot colour inks — there is no other way to replicate them on paper. Of course if you want metallics which are actually metal-like with a mirror finish, then foil blocking is the only option (see our previous post about that) but here we’re referring to inks which have metallic qualities without the mirror finish. There is even a Pantone colour swatch book for spot colour metallic inks and what it includes goes way beyond just silvers, golds, coppers, bronzes and gun metals. There are spot colours which include metallic greens, metallic pinks, metallic blues, reds and so on. Many are actually quite lovely and will give a real unusual quality to your printed document, particularly on coated paper, however metallic inks also benefit from a spot varnish coating — more about that below — so as to limit fingerprinting.
Varnishes and spot varnishes
Varnishes are also essentially ‘spot’ colours or at least spot inks to all intents and purposes. The pre-mixed varnish is printed in one pass via the litho press although if it is an overall, edge-to-edge varnish rather than in ‘spot’ positions, then it can be accomplished without a printing plate. As with spot colours, varnish can only be applied using the lithographic process i.e. is impossible on our digital presses — but that’s OK as we have both kinds of printing press!
It’s worth bearing in mind that you will require a new printing plate for every spot colour you need to print, apart from those edge-to-edge overall varnishes. So if you need 6 spot colours, you’ll need 6 plates so this will in turn affect the price. It works the other way too, however. A 2 spot colour letterhead litho printed in any large quantity will be cheaper than the same letterhead printed via 4 colour process (CMYK). It’s not quite true if small quantities are printed because digital printing works out cheaper than litho and spot colour for small print runs, although of course the colour matching isn’t quite as accurate as litho spot colour printing.
Free, expert advice from your local printer
So a balance needs to be struck and that’s where the experience and advice of Firstpoint Print is of real value. We’ll always tell you if there is a better, more accurate or more cost-effective way to accomplish your particular job. Firstpoint Print has 3 Central London branches: one in Clerkenwell EC1, another in London Bridge SE1 and a third in Victoria SW1. Click the links to contact your nearest branch and we’ll be happy to discuss your printing project, answer any queries and supply a price, all without obligation.