CMYK vs RGB

The questions have already started. The first one, and a quite good one actually, was ... why does the colour shift when moving from RGB to CMYK. Great question. Let's take a look.

Notice how small the CMYK gamut is within the larger RGB space. All of the space on the outside will have to be "mapped" or reassigned within the CMYK space upon conversion. This is when shifts happen. Knowing that it will happen is half the battle. Controlling how it happens is the other half.

This shift can make a huge difference, especially when dealing with blues and greens. In terms of identification ... we'll want to get it right.

So, when you are getting your files ready for print in your favourite publication (Evidence Magazine, or the like), controlling the conversion can go a long way in helping you make your case to your readers.

Enjoy.

working with colour - commercial printing part 1

The first question that I am asked, when dealing with the topic of sending items for commercial printing is: "in which colour space should I colour correct?" The answer is RGB.

Work the workflow as normal. All of your tools and plug-ins are designed to work in RGB. Remember that ProPhotoRGB gives us the largest gamut in which to work and correct our images.

Contact your print provider for the specific ICC profile for the output device. In this way, the conversion can be made at print time, leaving the original unchanged (this allows for the most flexibility but requires good communication between you and your print provider).

But what happens if you can't get a specific profile from your printer? Then ... we'll need to make a process specific CMYK image. One that's optimised for a particular device, ink set, and substrate (or we'll have to make a good guess). This will mean that the colours and tonal range will have to be changed, or limited, accommodate to the printing device in our final output copy.

Tomorrow, we'll look at optimising an image for CMYK output.

Happy Father's Day.

paying attention to the details

Forensic Dentistry Exhibit Uncorrected - from CMYK Print

courtesy of the Forensic Teacher.

When preparing your exhibits for publication, take care to note the type of printing process that will be employed. Four colour presses are notorious for blurring images and muddying colours. The CMYK process is quite different than RGB (subtractive vs. additive).

Forensic Dentistry Exhibit Corrected

Over the course of the next week, we'll take a look at commercial printing and preparing your exhibits for commercial presses. Many of us will have to prepare our cases to be shared in this way. There is a trick to it. The trick is to pay attention to the details.

Enjoy.