If you’ve ever had to get some work done by a printer, the chances are that it involved overlaying colored ink on white paper. Even in the typical home or office environment, you probably print colored images on white cardstock, paper, or some other type of neutral white material.
But have you ever thought about printing white? Is white even a printing color?
How White Is Handled When Printing
In most cases, the answer is: no, white is not a printing color. There are some exceptions to the rule, as we will explain later. But in the vast majority of printing tasks, white is not considered a color at all.
Why? Because, as we mentioned previously, printing usually involves transferring colored ink onto white paper, white cardstock, or some other form of white-colored media. Printing white ink on these materials is futile, as it simply will not show against the surface.
Try this simple exercise: go online and choose a full-color image with a good percentage of white areas. Print it out on your inkjet or laser printer and look closely at the white sections.
Do you see any colored dots? If the particular area is totally white, you probably won’t see even a speck of toner on it. It’s only when you move to the light-colored areas that you can make out spots of ink spaced at wide intervals.
Why do you suppose that is? That’s because most printers employ the CMYK color mode.
The Basics Of CMYK
With CMYK, colored images are produced by combining cyan, magenta, yellow, and black (“K”) ink in varying amounts. Printers use only those four colors on different cartridges, without any ‘white’ cartridges.
Because that particular area of the image is already white, there is no point in placing white ink on it. Even if your printer did come with a white toner cartridge, transferring white onto the already white paper would serve no purpose.
At this point, it might be helpful to know how the CMYK model works. Mixing CMYK colors is a subtractive process, which means that it works in conjunction with the white paper being printed on.
CMYK produces the same colors of the RGB (red, green, blue) mode that digital images typically use by combining the white of the paper with two or more of the other colors. For instance, printing cyan and yellow on white paper produces green. Yellow and magenta produce red, while cyan and magenta produce blue.
How is white represented in the CMYK color mode? By placing zero amounts of all four colors: 0% cyan, 0% magenta, 0% yellow, and 0% black. This means you aren’t transferring color to the paper at all. This lets the paper’s whiteness come through, which is how these sections of an image are rendered.
Printing On Non-White Media
Of course, all this assumes that you are using white paper stock. If you need to display a white area, all you have to do is leave out all the colors. Simple, right?
But what if the surface to be printed on isn’t white? Following the same process detailed above, you will have to deal with having the “white” areas of the image being the same color as the material. For example, if you are printing on brown paper, the “uncolored” section of the paper will also be brown.
Furthermore, the other colors will be affected by the brown of the paper as well. Combining cyan and yellow won’t produce the same shade of green as it would on white paper. It might look a bit green, but the chances are that the brown will make it considerably darker or ‘muddier’.
Remember we said that there are exceptions to the rule? This is where they come in. Some printers do have white ink cartridges, which can be used for “underprinting”. This refers to the process of coloring a non-white surface white to allow the use of lighter colors.
Underprinting essentially allows you to treat non-white paper as if it were white. With a layer of white ink on the surface, you could place any other color that would otherwise be affected by the non-white surface.
Underprinting is often used for printing images on clear cellulose, metallic material, and brown Kraft labels. Applying white on areas that will later be overlaid with other colors will make the surface opaque and make the resulting image sharper, clearer, and more vibrant.
The takeaway The bottom line is that white typically isn’t a printing color, but it can be with a specialized printing process. If you are working with a transparent or non-white material, ask your printer if they offer underprinting.