The reason I am posting this is that we have just had an incredibly complicated job go through the studio that involved the mystery of colour matching and I thought I'd try and explain a few things. So, in brief, this is how it went:
We had a client’s new brochure design to do and this was to match the colour on the previous brochure that was printed about three years ago using their own special Pantone Dark Blue. Simple?
Well no, unfortunately the previous job involved a press pass by the client. This is where they go to the printers and sign it off as it is being printed. When the press pass was done, the colour was amended whilst on the press and other colours were added to the mix and levels on the machine were played with. Meaning the special spot colour we thought it was, it no longer was. So, now what?
The printers helped out and sent the old brochure off to their colour chemists where they mixed up a match. Not as simple as it sounds either with each colour being affected differently by different stock (paper types) and coatings/lamination used. Although we eventually had a good solid colour to work with, we now had a new problem!
The new cover design used a pattern that was made up of various overlaying gradients of the spot colour. This, when printed in the new spot colour, did not match the CMYK representation the client had seen with it revealing much more contrast in the various blends. The client wanted the new colour but with the subtlety of the original design. This proved extremely difficult as the cost of testing a variety of blends on press was too much, so with only a calibrated proof to go on from the printers (this is a high quality digital print but does not print spot colours), we had a stab at which one of several cover variations was going to work best. This is probably on press as I type, so we will soon see the result!
During all of this we had to think of other material we are working on for them; business cards, folders and a newsletter. Throw into this the fact that the newsletter is being printed 4 colour CMYK, the folder 5 colour, the business cards 2 colour and the brochure will finally be printed 6 colour with a spot UV finish (but we will leave that one for now), it has created quite a headache in terms of colour consistency.
Did I lose you with all that? Well, this is why I thought I would take a little time out to try and explain the different processes in simple terms.
The subject of print colours can be lost on most non-designers. If I start to explain that the colours you see on your PC screen are not the same as print colours, that my screen will probably differ from yours and that your home printer is again very different to mine; I will no doubt find a very confused face looking back at me.
Right, the web colour spectrum is RGB, print colours are typically CMYK and Pantone and we will leave RAL out of it (used basically to translate into paint). Still here?
Sometimes it is necessary to try and educate clients on printing processes, and other times it can add extra complications they don't really need to know, however if it has an impact on the work, they need to understand what is going on and what could be the future implications. Hopefully there are then no shocks further down the line when the client receives their printed items.
CMYK Colour Printing
(Also called ‘process colours’)
Colour is produced on your choice of printed material (paper, vinyl, cardboard, fabric etc) by mixing four separate ink colours:
Cyan, Magenta, Yellow, and Black (CMYK).
Using this method can mean that when printing many copies of the same artwork, as is common with business cards and other forms of stationery, some areas of colour may not appear completely consistent. Consistency is affected by ink density, temperature, paper quality, and, when using CMYK, the colour can differ between printing companies. Generally, though the differences are very small.
Digital printers use the CMYK colour printing method. They can offer this at a very competitive price and allow short runs. You can print off a PDF document of your final design on a high quality office printer and get a close representation of the colours in your design.
This means that the finished CMYK print run should be pretty close to your office printer, however you can’t guarantee an exact match as stock (paper type) and the laminating process or coating can change the shade slightly on printed colours, as well as the heat at the time of print and so on.
If you wish to ensure that your logo design or company colour will print exactly the same on every single printed copy, you can specify what is called a ‘spot colour’. They are also guaranteed to look the same no matter which firm prints them.
There are a few spot colour systems available, but the industry standard is the Pantone System, each Pantone colour has a code – for example PANTONE 021 is an orange colour.
You can pick a Pantone colour from swatch books that display these colours and list the codes for each one (remember that when looking at a pantone colour on a computer monitor, it can look different from when printed and depending on which monitor you are looking at). Only by viewing a ‘swatch book’ can you see the actual colour as it will print. These are also pretty expensive to buy and if you understand this article and think about how they are printed, it makes sense.
You cannot view Pantone colours by printing a design file from your own office printer. This is because an office printer only prints in CMYK – therefore the only way to see accurate colours is to look at a Pantone colour book or see the design printed using the spot colour on the printing press.
The Printing Press (Litho Printing, Lithography, Offset)
These are extremely expensive machines and can vary in size. The basic principle is that it acts like a giant train, each carriage contains a large ink well and a rubber roller that holds an image of what each carriage is to print. These carriages connect together and the paper is fed in one end and passes through each carriage collecting an image of colour from each roller and ink well and is then spat out the other end ready for finishing (laminating, cutting, perforating, folding, stitching etc)
A typical large machine will me made up of six colour units, the first four will be made up of cyan, magenta, yellow and black (CMYK); leaving two more for specials (spot colours). A plate is rendered/etched with an image for each colour and is then transferred to the rubber roller that prints the image. I will leave how this is done for now to keep it simple, but may come back to it in another blog post.
So basically, the more colours, the more expensive, because each colour needs its own plate and space on the printer. Litho printing gives a much smoother print using the soft rubber roller compared to digital, so it is often used for large run four colour CMYK jobs, as the setup costs are outweighed by the print quantity and higher quality.
So Which Is Best?
- Specific colours which are consistent no matter who prints them.
- Vibrancy of colour that you can’t get with CMYK.
- Increased cost.
- Short runs become too expensive because of set-up costs. Due to the making up of each plate and the ink wells having to be filled with your specific spot colour; used then emptied and cleaned ready for the next job.
- Difficult to get an accurate colour representation before the job is printed.
- Low cost printing in multiple (limitless) colours
- Cheaper short runs for small orders.
- Lack of colour vibrancy … some colours can be a tad dull compared to what Pantone can offer.
- Cannot guarantee exact consistency of colours.
Most large clients end up with a set of guidelines that dictate things like colours and when they should be used. They will have a Pantone colour and an alternative CMYK version of the colour. This affects some colours more than others; an orange like ours is quite heavily affected and loses its vibrancy when printed in CMYK, so we add a little bit of red to the mix to give a stronger shade when printed digitally in CMYK.
As for our client that started this post. They will have a total of six colours to play with; they have the standard CMYK, a Spot Dark Blue and a special Metallic Silver. Depending on the job, these colours are used differently. For a four colour CMYK job, the alternative CMYK conversion for the spot colour is used and a grey (60% black) is used instead of the silver. Then when funds are available or the job warrants it, the specials can be used. Fingers crossed the colour comes out as we wanted and then all the info can be put into guidelines to ensure consistency.
I’m sure there is loads I have missed out here, as it is such a vast subject, but I hope this gives you a brief understanding of colour or an insight for any student’s reading into another side of being a designer. As 95% of my knowledge on this came after leaving university, it is something I wish I’d has a better knowledge of when going into the working world.