Optimised RGB to CMYK Conversion

Especially when defining corporate designs, RGB is often used. A new trend is to create corporate designs "Digital First" from the outset and thus in sRGB. But what if these colours are to be reproduced in four-colour print for brochures? For some colours, there may be CMYK values available. But are these really the optimal colour values? And what if there are no CMYK values for your RGB colour, or the RGB colour is significantly brighter than your CMYK target colour space? What then is the optimal RGB to CMYK conversion?

Converting RGB colours to CMYK presents numerous difficulties

• Do you need CMYK data for sRGB or AdobeRGB colours on brightened natural paper according to PSOUncoatedV3/Fogra 52 or for printing on cream-coloured paper? Here, the PANTONE Bridge CMYK values usually produce poor results because they were not designed for these standards. 
• Do you have RGB values and CMYK values determined with a CMYK fan for picture printing, but still need matching values for natural paper and newspaper printing?
• Do you only have a material sample such as a powder-coated surface for which matching CMYK values are to be determined?
• Do you need a natural paper CMYK value for a film colour such as Oracal or a coating colour such as RAL?
• You are producing packaging in a vibrant, bright PANTONE red. If the product name is in white text on the packaging, you would certainly prefer a saturation-preserving but slightly darker conversion of the PANTONE tone for readability. If the product name is in black text on the packaging, you would prefer a brightness-preserving value with lower saturation so that the name remains more legible.

We supply optimised, individual CMYK values for the conversion of spot colours

In a multi-stage process, we determine your optimised CMYK definitions

1.: Measuring the original template

If you have a PANTONE colour as a reference, we determine the LAB value specified by PANTONE for the conversion. Since the PANTONE fans sometimes deviate noticeably from the own LAB values, we additionally measure several fan colours and compare the values. In consultation with you, we select the fan colour or the digital reference as the basis for our further steps.

2.: Determining different basic conversions

Based on the selected colour reference, we develop five to six different CMYK conversions based on different rendering intents for your selected output process, proof these and measure the various colour fields. We send you this conversion and use this first selection to establish the basis for the next optimisation step.

3.: Determination of variances for visual optimisation

In the next step, we create a matrix based on the best CMYK conversion from step 2. Using software, we develop and proof a systematic colour matrix to visually verify the selected conversion once more and optimise it if necessary. By varying the chromatic colours in each case plus/minus two levels from the starting value, between 25 and 125 variations of the originally selected colour are created for visual alignment. You can find a graphical example in the product images. Based on the selected base colour, you can fine-tune the conversion of the final colour values. To make your selection easier, we provide you with metrological evaluation in Delta-E for the individual colours for the most important values.

For each colour to be optimised, you receive several proofs with test reports and metrological evaluations in Delta-E00.

The price applies per spot colour and per output condition. For example, if you want optimised CMYK conversions for a PANTONE colour for coated, uncoated and newspaper paper, you must order the item 3 times.