What is the difference?
Colors created for use in print projects fall into two categories:
'Process screened colors'
Process Colors are created using screens of Cyan, Magenta, Yellow, and Black, which are used in creating 4 color process images, like the images below:
Over 3,000 Pantone process colors , and their screen values, can be found in the Pantone process guides set ctd/unctd..
Spot Colors are created using a print of a Pantone solid color, such as Pantone 185 red image below:
In the example above, Pantone 185 Red is printed as a solid, by using Pantone 185 red ink. There are over 1,114 colors in the Pantone solid palette, and yo can find them in the Pantone solid formula guide set ctd/unctd.
If we compare how the same color looks as a spot color vs. a process build color, the image below has Pantone 185 red solid on the left, and the CMYK build (92% screen of Process Magenta , and 76% screen of Process Yellow) on the right.
As you can see, the colors do not match exactly, which is why the Pantone color bridge is such a useful tool.The Pantone Color Bridge set ctd/unctd. has all the Pantone solid colors, side by side, with the CMYK color build on the right, so you know exactly how Pantone solid colors will look when reproduced in CMYK. As an added bonus, you also get RGB and HTML hex codes for web design.