The fascinating journey of a single pixel

An idea is born, and the journey of a pixel begins. A single pixel will take on many forms until it finds its final resting place. Let’s follow this pixel throughout its remarkable journey and watch the colour transformations it takes along its way. Our pixel emerges from a dream as light is captured onto a camera’s sensor: R6, G84, B244 is born. For those of you who don’t speak RGB, it’s a beautiful, out-of-this-gamut blue. It’s one of those colours designer’s dream of and printers long for. For this little pixel, life has just begun – but it still has a long way yet to go. So who is R6, G84, B244? Without anything tangible to assign to it, the values have no meaning. R6, G84, B244 needs a way to express itself and that vehicle comes in the form of a colour space. We need to plot this colour, put a stick in the ground to give it a tangible value. An RGB colour space can come in many flavors: sRGB and Adobe RGB (1998) are the most popular.

The RGB colour space you decide on is based on a few factors. What’s the intended final resting place for R6, G84, B244? If our pixel will never see anything other than the web, then sRGB makes sense. But if you’re planning on brighter and more saturated dreams for our pixel, then Adobe 1998 would be a better choice. Adobe 1998 works best for printing in CMYK, and ProPhoto is a good choice for long-term archival and the latest generation of high-gamut, multi-colour inkjet printers.

How do we translate from one language to another? This exchange is facilitated using a ‘dictionary.’ In the case of colour conversions, we use ICC profiles to describe the starting place and the destination. Every colour conversion has two essential components – source and destination. In many cases, Adobe RGB is the source and Coated GRACoL 2006 is the destination.

Now our pixel is growing up and needs to express itself. It needs a way to show itself and for this pixel its vehicle is your monitor. But how does the monitor know how to display our cute little R6, G84, B244 friend? There are a few factors at play here. First is the colour space that our pixel resides in, and the second is the ICC profile for your monitor. Without a monitor profile, our pixel would be just any other pixel. But with a monitor profile, we can properly display our little blue friend. Now that the video card and OS are armed with all the information, it sends the instructions to the monitor powering the RGB phosphors. The good news is this happens a lot faster than it takes to read this. So, pixel R6, G84, B244 is accurately displayed on screen, but are we done? The answer is yes if the monitor is all we hoped for from R6, G84, B244. But if this pixel is to see the light of day, we need to continue down the road to where the ink hits paper.

Here we have a few options when it comes to making the conversion to CMYK. But before we go to the mode CMYK menu option, we need to determine the best flavour of CMYK. The first question that needs to be answered: is the job going on a sheetfed or web press? Next, is the paper coated or uncoated? Once you know the answer to these questions, you can select the appropriate profile and Photoshop a number of options to make this conversion.

Now R6, G84, B244 has grown up and become Cyan 88 and Magenta 58 on a sheetfed coated press – or Cyan 87 and Magenta 67 on a web press. As you can see, the profile you select has a big impact on the way our purple pixel ends up. The lesson learned here is to always be aware of the settings and options before you make that CMYK conversion. Finally, I hope your pixels grow up to be a bright and colourful as you’ve always hoped!