Optimised RGB to CMYK Conversion

Especially when defining corporate designs, RGB is often used. Another new trend is to create corporate designs "digital first" and thus in sRGB. But what if these colours are to be reproduced for brochures in four-colour printing? For some colours there may be CMYK values. 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 much brighter than your CMYK zile colour space? What then is the optimal RGB to CMYK conversion?

There are numerous difficulties when converting RGB to CMYK

• You need CMYK data for sRGB or AdobeRGB colours on brightened uncoated paper according to PSOUncoatedV3/Fogra 52 or for printing on a cream-coloured paper? Here, the PANTONE Bridge CMYK values usually deliver poor results because they were not created for these colour standards. 
• You have determined RGB values and CMYK values with a CMYK fan for coated papers, but still need suitable values for uncoated paper and newspaper printing?
• You only have a material sample such as a powder-coated surface for which you need to determine suitable CMYK values?
• You need a natural paper CMYK value for a foil colour such as Oracal or a lacquer colour such as RAL.
• You produce packaging in a strong, bright PANTONE red. If the product name is written in white on the packaging, you would surely prefer a saturation-retaining, but somewhat darker version of the PANTONE tone for the sake of legibility. If the product name is written in black on the packaging, you may prefer a lightness-preserving value with less saturation to make the name easier to read.

We provide optimised, individual CMYK values for the realisation of spot colours

In a multi-stage process we determine your optimized CMYK definitions

1: Calibration of the original template

If your reference is a PANTONE colour, we will determine the LAB value specified by PANTONE for the implementation. Since the PANTONE fans sometimes differ noticeably from our own LAB values, we additionally measure several fan colours and compare the values with each other. In consultation with you, we then select the fan colour or the digital reference as the basis for our further steps.

2: Determination of different basic conversions

Based on the chosen colour reference, we develop five to six different CMYK conversions using different rendering intents for your chosen output process, proof these and measure the different colour patches. This implementation is then sent to you and, based on this initial selection, we determine the basis for the next optimization step.

3: Determination of variances for visual optimization

In the next step, we create a matrix based on the best CMYK implementation from step 2. Using software, we develop and proof a systematic colour matrix in order to visually check and, if necessary, optimise the selected implementation. Through a variation of the CMY colours in plus/minus two steps from the initial value, between 25 and 125 variations of the originally selected colour are created for visual matching. A graphic example can be found in the article pictures. This allows you to finetune the conversion of the final colour values based on the selected base colour. To make the selection easier for you, we provide you with a measured evaluation in Delta-E for the most important individual colours.

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

The price is per spot colour and per output condition. If, for example, you want CMYK conversions optimized for a PANTONE colour for coated, uncoated and newsprint, you must order the article 3 times.