File Preparation


Colour Mode

CMYK is the industry standard for offset printing and you need to submit your files in CMYK colour mode. If your files use RGB colour mode, you need to convert them to CMYK to avoid unexpected surprises. The same applies to spot colours.

We recommend you do the colour conversion to CMYK yourself to be aware of possible colour shifts (if any). This way you have a chance to react on them and change hues to acquire the desired look and feel. Depending on your colour choices, colours may appear dull and washed out when converted to CMYK as shown in the image below.

Colour Appearance

Note that your monitor does not accurately display the colours as they will look in print. In general, colours look brighter on screen.

Please ensure to set your graphic software to display exact black values instead of defaulting to rich blacks. This will prevent misprints based on uneven black values in your design.


Incorrect Use of Spot Colours (Pantone etc.) in CMYK Printing

Please check the print files for your 4/0 or 4/4 orders thoroughly to ensure no spot colours were used in the creation of your design. Unfortuantely we'll have to decline files containing spot colours for process colour print jobs, and will ask you to upload corrected CMYK files. 

In InDesign, you can convert spot colours to process colours using the Ink Manager during export to PDF (step 5). In Illustrator select everything in your document and choose Edit > Edit Colours > Convert to CMYK. This will convert all spot colours to process. 

An automated conversion of spot colours to CMYK comes with a high risk that design elements vanish or are displayed incorrectly. To prevent these types of print errors and save yourself the troubles of misprints and/or delays, please check the file and ensure only CMYK colours are used before submission.

One exception are CMYK prints containing Spot UV or special shape die-cuts - in these cases only the Spot UV or Die-Cut markers should be created as spot colour with overprint setting assigned to all elements. 

Colour Density

  • High Density: A very high application of ink in one spot may not dry properly and result in smear. We do not recommend using a colour density higher than 300%.
  • Low Density and Gradient Colour: Working with a very low colour density (up to about 10 or 15%) always incurs a certain amount of unpredictability. Depending on offset ink application and the paper used, the colours might have a diminished visibility, and gradient designs (fades to white and crossfades) might not start or end exactly where you intended.
  • Rich Black: If you have a solid black area in your artwork, set the colour values of that area to the following combination to achieve a rich black: C 60%, M 40%, Y 40%, K 100%.
  • Registration Black: Never use 400% black in your artwork! This black is reserved for printers' marks and not to be used in your design. We will decline these files and ask you for a corrected upload. Please check your blacks in advance to avoid unneccessary delays. For rich black please use settings as indicated above.
  • Black Text: We recommend the use of 100% K for black text. This is especially important for small font sizes. 


How do I prevent blue colors turning purple?

Blue is, similar to bright red and bright green, a primary color of RGB spectrum. For that reason, the color changes will be most significant when those colors are converted to CMYK.  However, when working in CMYK mode there are still rules to follow if you don't want your dark blues turning purple: 

Royal Blue is often mistakenly created with an even amount of Cyan and Magenta. While this may look bright blue on your screen, the result of e.g. 100% Cyan and 100% Magenta in print is a purple mix. Typically the strongest blue you can create with CMYK colors consists of 100% Cyan and 70% Magenta. If you add more Magenta, the print result flips to purple. Add black and yellow if you need a darker shade of blue.If you have 0 in the Black channel, and your Cyan is above 70% there will need to be at least a 35% difference to your Magenta value to attain blue. If Cyan is below 70% it will have to be more than 40% for coated paper stock. The lighter your shade of blue, the greater the difference needs to be. If the shade of blue is important to your design, we recommend working with a CMYK swatch book for color references, or the use of Pantone Spot Colors (see Information below).

Important Note

While we try to achieve the best possible result, we cannot guarantee accurate colour reproduction and we will not refund or reprint an order because of colour variation. Please read our Terms of Service.

In case you need an exact colour or colours that cannot be represented through CMYK, we recommend using HKS or Pantone. If you can’t find that option for your product, please send us an e-mail or use our custom request form.

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