When creating an artwork for print, always ensure you are working in CMYK colour mode. This will allow you to work in the correct colour space for print and will increase your chances for colour accuracy.

When supplying an artwork for print, always ensure the colour mode is set to CMYK, with the profile set to Coated Fogra39. This will give you a snapshot of how the artwork will look when printed, just be aware that all monitors can display differently and that this is not a proof.

If colour accuracy is your top priority, then always get a printed proof. Every printer has a different colour gamut available to it and each has a different colour gamut depending on the substrate it is printing on. This can be even more pronounced when using different modes of print, i.e. UV print or Dye Sublimation print.

If the artwork contains any RGB elements and once converted to CMYK, there is a chance for colours to change/shift. This can happen as RGB colour space has a much larger colour Gamut available to it, particularly with bright vibrant colours, and once converted to CMYK there is a chance that these colours will dull down noticeably.

Here, I have an artwork set to RGB mode with a selection of RGB colours:

But once I change the colour mode to CMYK, the colours change fairly drastically:

Again this is due to the limited colour space of CMYK, see below a representation of the different colour spaces:

The vibrant colours have changed more than the darker colours, as RGB is screen colour, and this is generated by light and is an additive colour. CMYK uses ink on a white surface, this is subtractive colour.

When RGB colours dull like this, it is down to the designer/artworker to manually adjust the colours to try and bring back their vibrancy.

This can be achieved by manually adjusting each colour's CMYK values, but be careful when using the colour picker, Illustrator will warn you when a selected colour is out of gamut:

If you then click on the icon it will then select a colour closest to your selection within the CMYK colour gamut:

Again, it is down to the designer to adjust the values until they are happy and are no longer getting the "out of gamut" warning.

We recommend checking the colour profiles of any artworks supplied to you. European printers all use Fogra39 as standard. Some artworks may have come from America and have embedded profiles such as - U.S WebCoated (SWOP) and again when converted to Fogra39, there is a chance for colour change. 

We have our colour settings to preserve embedded profiles, this is to avoid any surprise colour changes for our customers but due to this, if the supplied files have strange, non native profiles attached, there is a chance for colour issues to arise. 

Spot Colours

Many artworks we receive contain spot colours, such as Pantones and RAL colours, our RIP software will detect these and use its own library knowledge to try and print these accurately. Just be aware that some colours may be outside of the printers colour Gamut. If you have any concerns with a Pantone/RAL, please let us know and we can give you the Delta E (dE) score of the spot colour, any number below 3 should be a close match to the colour, but again, a printed sample is the safest bet with any colour concerns.

Spot colour Guide

Name your spot colours carefully, any misspelling can cause the RIP software to not recognise the colour.

Spot colour named correctly:

Spot colour misspelled:

In the above example, our RIP software cannot find the spot colour in its library and will then default to using the ICC profile, the CMYK values within the spot will now be used to calculate the LAB values.

When using Spot colours, be aware that the CMYK values contained within the spot colour will be ignored by the RIP software, it will use the information contained within its library to create the colour.

A safe bet is to only use known Spot colours such as Pantone, HKS, Ral, making a custom spot colour has a risk of confusing our RIP software, it is always far safer to make any custom swatch a process colour, rather than a spot colour.

Greys

It is recommended to set greys within your artwork in graduations of black, i.e 50% 60% 70% etc with minimal additional colour CMY. Creating greys using 4 process colours has an increased chance of colour variation when printed, especially over different substrates, and increases the chance of appearing black.

If a grey has a large total ink volume - 69/73/60/83 its total ink is 285 and will appear grey on screen, but when you consider that on some of our substrates, our rich black settings are 50/50/50/100, a total of 250 ink, it is hardly surprising that when printed, the grey turns black.

Here I have an example of a screen grey and how it will appear when printed:

As you can see, the grey on screen appears noticeably different to the black, but when converted to CMYK print, the total ink volume will turn the grey to a very subtly different black; which due to the nature of digital print (using dots of ink, making the print grainy over litho print) will be lost to the black next to it.

We strongly recommend that any greys you use be made up of predominantly black, with very low levels of Cyan, Magenta or Yellow.

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How to achieve good blacks

Achieving a good Black is tougher than most people realise, every printer; when profiled, can give a different black at different values.

Plus you have the added issue of artworks being set up for litho printing, digital printing and web. 

Each of these mediums have different preferred black values - true black in RGB (web) will convert to C86M76Y66K92 which isn’t ideal for digital print and will, more often than not, make the black visibly more blue/red/muddy and can cause other issues of over saturation and bleeding.

The safest bet when it comes to black setup is to use these values for UV printing, (which includes all our non fabric substrates) - C50M50Y50K100

For Fabrics we have different values based on the material.

Our Flag printers will give a quality black with just 100k.

Our other fabrics - Stretch Display and Backlit polyester prefer a set up of C75M65Y65K100 to achieve a deep and rich black.

It is highly recommended to avoid registration black - C100M100Y100K100, this will give a muddy colour and will also cause issues like bleeding/ghosting.

If you have images where the black values are very high and contain lots of mixer values i.e. C87M73Y69K100, it is recommended that you adjust the images within photoshop to bring down the values to sensible levels or you risk losing details within the image due to the printer putting down too much colour.

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Wet Proof

Ultimately, the safest bet with any colour concern is to have a printed sample.

We provide this service for a small fee and highly recommend it with any large orders, this provides peace of mind for yourself and hopefully, a happy customer.