RGB color: coding for the colour composition

 
One of the first step to undertake before starting a new graphic project is surely the choice of the colour mode. Depending on the product intended use – whether for the web or for printing – it will be necessary to choose the most appropriate colour coding.

 

What are color models and why are they important for graphic projects

Color models are a system to represent an image with some primary colours that – thanks to their fusion – generate all the others. The two most common color models of digital graphic are RGB and CMYK, also called three-colours or trichrome and four-colours respectively.
As a general principle, the first method is used to elaborate images for the web or tv, while the latter is to be used when the final use is printing. There are also other, less common methods such as gray scale and Lab.

RGB colors vs CMYK colors

 

How does trichrome work

As can be easily inferred from its name, trichrome is based on three colours: Red, Green and Blue. RGB colours are obtained with the additive method, that is, an array of colours is generated by the mixtures of light of these primary colors. The brightness of every channel is expressed with a number ranging from 0 to 255, corresponding to the minimum and maximum of intensity: a colour in the RGB model is therefore identified by three number. Turquoise, for instance, corresponds to 64; 224; 208. Summing up the three colours at the highest intensity (255; 255; 255) you’ll obtain white, while with the three channels at 0 intensity, the result will be black.
 
Since almost all the screens obtain the colour chosen by mixing the three colour pixels (RGB) and by adjusting their brightness, trichrome is the method used for web and for the visualization of graphic elaborates and photography on the display. RGB method allows to obtain a wide array of colours with vibrant hues.

 

CMYK colours

The CMYK acronym indicates a colour model also called four-colours and therefore based on four primary colours: Cyan, Magenta, Yellow and Blac k. Unlike trichrome, CMYK colours are obtained with the subtractive method, that is other colours results from subtracting brightness to the four primary colours.
CMYK model is used exclusivelu for printing: on graphics editor, colours values are expressed with a percentage associated to the quantity of ink for every colours: when all the percentages are equal to zero, no ink is printed and therefore the result will be the colour of the chosen support.
If compared to RGB color, CMYK has a more limited colour array and less intense shades.
 
 
Cmyk

 

 

How choose colour profile?

As mentioned before, RGB colours is to be preferred when working for the web while CMYK profile have to be used for printing. The most important graphics editors offer the possibility to choose in advance the colour profile and also the opportunity to convert images by switching froma model to the other.
 
 
 
Obtaining printed images completely loyal to those displayed on the screen is, however, a more complex operation than the simple conversion proposed by graphic editors since several variables are involved from the printer model to the support chosen.
 
 
For this reason, if you desire to print your label our suggestion is to work directly on a CMYK file or to convert the colour profile directly at the end of the entire work: if you have any doubt concerning the conversion, contact our team (link)! We’ll help you obtaining sticker labels with perfect colours!
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