A customer receives delivery of their order of posters that they ordered online using a file they created and submitted with the order. They are horrified that the main colour blue they wanted for the sky is almost purple and not what they saw on their computer monitor when they designed it.
Creating and reproducing specific colours is a bit complicated but very manageable with a bit of knowledge. It has been my experience that most clients are looking for ‘something close’ colour wise unless we are talking logos or other branding requirements. It is however, good to be as precise as possible to enhance the final results regardless. This starts with the design.
First of all, your monitor shows colour using RGB (Red, Green, Blue), which are the primary colours of light, as do digital cameras, TVs and all light emitting technology. It is the percentage of each component that determines the final colour.
Printing uses CMYK (Cyan, Magenta, Yellow, Black) to produce colours, which can’t produce as wide a range of colours as RGB and in addition, doesn’t have the benefit of backlighting to make it appear brighter. In offset printing this is referred to as 4 colour printing. Digital colour laser devices generally use toner vs. ink which behave differently but still formulate the colours using CMYK.
Thanks to Wikipedia and pantone.com for these graphics, which shows how the subtractive colours when combined create other colours. The percentage of each primary colour, plus black (the Keyline colour, hence the ‘K’), determines the final colour.
In addition to CMYK, spot colours are often used when exact colours are required in addition to CMYK or only one or 2 colours are being printed. These are exact colours of ink directly printed so the only variable with them will be density.
Thanks to pantone.com for the graphic below, showing a red being mixed, note the PMS swatch beside from which the mixer gets the formula by percentages to create the colour desired. eg. PMS 185C = 75% Warm Red, 25% Rubine Red or a 3-1ratio where Warm & Rubine Red are standards. Scales are used to weigh/measure the amounts of the components.
The CMYK formula for the same colour is C-0 M-100 Y-75 K-4.
The numbers indicate the coverage of each particular component. Note that the PMS number has a ‘C’ after it. This refers to coated stock, ‘U’ would mean uncoated.
As an aside, the RGB formula for the same colour is R-224 G-0 B-52, but it is important to note that it is not exactly the same colour as the CMYK or the spot colour on the PMS swatch. This is because the colours will be different when displayed in different media (monitor vs. paper). You can see how problems can arise so it is important to be on the same page with your Printer.
Exact colours are identified and catalogued by numbers in the Pantone Matching System (PMS). There are numerous swatches with thousands of colours that will identify something very close to the colour you want.
Here is a graphic from pantone.com of a couple of their many swatches.
The paper that it’s going to be printed on will vary the colours as well.
In fact PMS swatches separate colours between coated (glossy) and uncoated stocks and the same PMS colour is not necessarily exactly the same in formula or final colour (see above graphic). Glossy paper will appear brighter than uncoated paper in offset printing because of ink absorption. This is not necessarily true with colour laser copies. Most offset ink is not like paint, it is partially transparent, so printing white on black stock will yield a gray. If you see white type on a dark coloured substrate generally the dark colour was printed leaving the type white substrate to show where the type is. This is called reverse printed type. Metallics are an exception to this. Laser toner is more opaque than ink and is not as affected by substrate texture or colour.
The PANTONE® FORMULA GUIDE with 1,114 PANTONE MATCHING SYSTEM Colors on coated and uncoated stock.
These are not inexpensive and the average person is not going to buy them but you can usually identify the colours by PMS number or a CMYK formula on your monitor if you are using a decent graphics program.
If not and you are fussy about a specific colour, talk to your printer and ask them to show you a swatch.
They should have a few of them with different configurations.
Also, spot colours are not necessarily exactly the same as CMYK colours. Generally spot colours are considered more accurate because the ink is mixed beforehand using other spot colours to create that colour, not relying on the limitations of CMYK formulas. There are separate PMS swatches for spot colours and CMYK colours, along with a few more configurations.
Identify with your Printer how the job will be created. Proofing on digitally produced jobs is simpler and less expensive than offset but what method is best for your job will depend on the capabilities of the Printer’s equipment. There will be a difference between digital and offset ‘look’ but a digital laser proof will give you a general idea of the final result of an offset job.
To summarize (and simplify) so far, – Monitors, T.V.s and digital camera use RGB to create colours while printing uses CMYK
– Specific colours can be identified using the PMS number.
– Keep in mind the substrate (paper or whatever) that is going to be used can also affect the colour.
– Get a proof of some sort to show you how the final result will look like.
– The main point is that different media will display the same colour differently therefore the formulas to create them are also different.
So what do you do if you want to design a piece and produce a specific colour or colours?
– First of all, was your monitor calibrated recently, or ever?
Digital devices in our shop are calibrated almost daily to ensure proper representation of the colours intended.
While very few monitors have and likely never will, you need to understand that this will have an effect if your monitor is way off.
As stated above, you usually can identify the colour if you are using a good graphics program.
– Don’t create the piece using RGB. You may head off some problems if it’s in CMYK.
– Identify any specific colours required with your order keeping in mind that different devices will give you different ‘looks’. Speak to your printer beforehand to get an idea of how the piece will be best created.
If you have any doubt, talk to your printer to ensure that you’re going to get what you want.
Ask to see a PMS swatch if need be.
A colour laser, while not exact for offset printing, will give you a reasonable idea of what you are going to get and is not expensive.
If you want more and it is being produced offset, ask for an accurate proof. It will cost more money, but show you exact colours. This what the press operator would use, if available, for reference when the job is printed.
Colour Management by no means ends here. In fact it gets more complicated and device specific. This is intended to be an overview of the basics, perhaps I’ll elaborate on the finer points of what I’ve mentioned in future entries.
Any feedback on this or any other blog entry would be appreciated.
You can contact me at [email protected].