These processes were meant to APPROXIMATE the selected color of how it will look when printed. Unless you have gone through an extensive color calibration process these devices each shows colors differently. You can take the same image on 5 monitors and it will look different on all of them. The same will occur when printing out to 5 different laser/inkjet printers. Each device has different degrees of calibration that are possible.
A monitor displays color in RGB (red, green blue). Colors are created by adding red, green and blue light (additive process). Offset printing will typically be either CMYK (cyan, magenta, yellow and black) or PMS Colors. Inked paper absorbs or reflects specific wavelengths (subtractive process). Cyan, magenta and yellow pigments serve as filters, subtracting varying degrees of red, green and blue from white light to produce a selective range (gamut) of spectral colors. PMS Colors are specially formulated colors that don’t always have CMYK or RGB equivalents.
Both RGB and CMYK can only represent at best a relatively small part of the total color space, and there are some colors that can be produced in one but not in the other and vice-versa. The range of color that a color space can produce is called the gamut.
Another element that affects the way the color will look when printed is the stock. An uncoated stock will absorb more ink creating a heavier image. On a coated stock the ink will typically sit more on the top of the surface. The coating on the stock had a different reflective property creating more vibrant images. If the stock has a color to it the inks will be affected by the color. If you print a light blue on a cream stock that light blue will have a tinge of green to it. When using special or colored stocks it is best to ask for ink drawdowns on the actual paper. This will give you a better idea of how the actual color will look. Something to remember with drawdowns - an ink draw down is created by putting the ink onto a paper by hand without water — when you actually get on press and add all the other elements in there can be a slight variations when on press.
For CMYK offset printing we recommend a matchprint proof to show how the color will print on press. The matchprint device has been calibrated to match the printers press. Each press will print a little differently (some may be heavier reds, some may be heavier cyan.) Matchprints can be calibrated to show the difference in what happens to an image on Coated vs Uncoated stock. This will help to eliminate any surprises on press.
PMS stands for Pantone Matching System. The Pantone matching system was created to universalize and standardize the selection of ink colors and is broadly used through out the world. It gives the color a number that is easily ordered by the printer and gives the client a way to select colors with relative assurance of the outcome from one printer to another. Pantone prints various different guides for matching colors. These guides are used through out most print shops creating a common language to speak about colors.
Pantone guides are available on coated, uncoated and matte stocks. The reason they are made for different types of paper is because each paper has different reflective and absorption characteristics. The same PMS color on a coated stock can have a very different look when printed on an uncoated stock. When looking at PMS swatch books you always want to be looking at the correct book for the type of stock you will be printing on.
Pantone makes a very useful swatch book called the solid to process book. This is a “must have” tool for anyone who designs project with PMS colors and then wants to print them as 4CP. Not all Pantone colors will convert to CMYK well. Some colors will have a drastic color shift – others the difference will be barely noticeable. This swatch book will show you the PMS color and how it will print in 4CP. It will help you to determine if that 5th color is really necessary for a project. The following image on the left shows the PMS Color. The right side of the strip shows the CMYK match to the color. You can see that in PMS 1767 the CMYK is not as rich of a color – it becomes muted. For PMS 1817 the CMYK equivalent becomes much heavier and darker loosing the brightness of the color.
We here this term thrown around in relation to the environment and inks. So what does it really mean.
Volatile organic compounds (VOCs) are organic chemical compounds that have high enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. When VOCs are released into the environment they can damage the soil and ground water. Vapours of VOCs escaping into the air contribute to ozone depletion and air pollution.
The inks we use in the printing and engraving processes are low-VOC varieties to help minimize the effects on the environment.