A deep dive into color modes
You're in the midst of a crucial process: preflight. This process involves very specific techniques and rules to enhance print quality and reduce costs. As we've discussed in previous articles, we're going to delve into the important parts of preflight, and now it's time to review color modes. As a prepress professional, once you've prepared your preflight checklist, the first step is to verify whether the submitted file is in the correct color mode for the printing process and device. But why do we start with this?
Imagine building a 50-story tower on a foundation that can only support two stories. What do you think will happen to that massive tower? Your tower is the same file and troubleshooting is the same preflight. Building this tower is also a matter of printing.
I've often encountered situations where a designer, after finalizing a design and getting client approval, asks me to send the final file to the printer. To my surprise, the first thing I notice is that the designer has chosen the wrong color mode!
In such cases, all the color code adjustments, shadows, and black codes are rendered useless. So, the first step is to create a suitable foundation for the design file. The fundamental question is: Which color space is right for my project? Bitmap / Grayscale / Duotone / RGB / CMYK / MULTICHANNEL / LAB
A journey through color and light
Each of these color modes has a specific purpose, so we need to understand which one is most suitable for our company's printing activities. To begin, let's take a journey into the world of color modes. Every file, after being designed, standardized, and printed, is intended to be viewed by a specific target audience. Therefore, the first important thing is the range that the human eye can perceive.
Do you remember when we used a prism in school to split white light?
Did you notice the spectrum of colors? The initial, middle, and final wavelengths are the parts to which the human eye is most sensitive. What do you see? Blue, green, red. Yes! That's how the three primary colors of light were defined. So, these items are defined based on precise logic and principles. This is the simplest explanation of RGB. Now, imagine yourself in a completely dark room. I'll turn on three lamps of equal power with these three colors and I combine both colors from the light system.
What new color will the overlapping parts of the two colors tend towards? That's right, CMY is the result of the overlap of these two colors from the world of light. These colors will have many applications in printing systems in the future, and their settings and descriptions will be provided to you professionally. Until then, we still have many questions to answer...
A deeper look
- Why does the combination of red and green produce a color as bright as yellow? Aren't they both dark?
- Answer: Because these are lights, not canvases painted with acrylics.
- Why aren't the primary colors in printed files the same as the red, green, and blue colors?
- Answer: Because experiments conducted with RGB resulted in outputs that were not suitable for printing.
We have an experiment to create colors and explore some of the questions above. In this experiment, RGB rays were shone onto surfaces made up of RGB and CMYK colors. To better understand this, let's simplify the experimental process with an example: Here, we'll choose item B from the RGB group and item M from the CMY group as representatives (you can experiment with other items for better understanding).
The light source was shone onto the blue surface and then onto the magenta surface, and the results were re-examined. Based on what you see in the top image, in the second case, more color outputs were obtained, which led to the selection of CMY colors for printing to achieve greater color variety.
Always Present: Black
Black is not considered a color and is classified as achromatic. Because the combination of CMY doesn't give us a deep black, the color Black was added to be used for pure blacks. In this way, the CMYK color space was created.
As you know, this was a significant and key event, and the letter K was added to represent Black in printed colors. Perhaps choosing the letter B would have made it similar to Blue, which is why it's not represented by that letter!
Important Factors in Color Perception
There's a very important point to consider in this process. When a color is printed on a material, several factors influence our perception of it. For example, the fact that the blue color in your mind or on your monitor differs from the color you see when it's printed on different materials, and the fact that different people with different emotions and ages perceive it differently are all part of the color quality control process during printing.
- What kind of light source is shining on the material? Sunlight, fluorescent lamps, and LEDs have different intensities and can change your perception of color. So, a standard light source is important in the final result.
- What material is the color printed on? Will the same blue that's printed on glossy paper produce the same result on plain paper? Certainly, the type of material and even the type of printing device will create changes in the produced colors.
- Who or what is the observer of the color? Is the observer a thin, vegetarian with a calm temperament or a nervous person? Perhaps the observer is someone who constantly consumes fatty foods and is overweight; maybe the observer is a camera. Each of these has a different perception of that color. Be assured that feelings, physiology, and even the time spent looking at the color can cause variations in the final result. Even if the quality control officer is wearing the wrong glasses, they will see a slight yellow tint on all colors.
- At what angle does the light shine on the material? And at what angle does the observer look at the surface of the material? The correct viewing angle, the intensity of the incident light, and the viewing angle of the quality control officer can produce different results.
These key questions lead us to the color space that allows us to introduce the principles of color space, color management rules, and international color standards, independent of personal opinion and taste. That color space is LAB, and subsequently, we will also explore HSB.
Now we understand why when we open the Color Picker, we have different color selection items available. Therefore, we will learn how to choose the correct color based on human perception and then standardize it according to printing rules.
