How to Printers (printing machine) handle Spot colors and Process colors

[OssodiSeppia]

I am a self taugh novice and need to have a bit better understanding of how colors are handled by printing machines.  I am using the word machine so that no one thinks I am talking about a print shop.  🙂

I am planning on supplying someone with a pdf  to use for dye sublimation on some coffee mugs.

Will a process color print the same as a spot color, if they both are set up with the same, RGB, Lab or CMYK values?  Thank you.

[Ton Frederiks]

"Will a process color print the same as a spot color, if they both are set up with the same, RGB, Lab or CMYK values?"

No, a spot color is a single mixed ink. CMYK describes a color in percentages of the 4 process inks,  Cyan, Magenta, Yellow and Black and is for printing. RGB values describe color in various amount of Red, Green and Blue light and is for displays like monitors. Spot colors are generallt used to mix colors that cannot be created with standard CMYK inks.

[OssodiSeppia]

Thanks for the prompt reply.  I understand a spot color is a single mixed ink.  If a spot color is defined with the same values as a process color, should they not print the same?  The two swatches I've posted use the same color values R-242 G-204 and B-54.  Will these no print the same?

[Ton Frederiks]

RGB values are not inks, they are monitor/display colors made with light.

They can be converted to CMYK inks, but these use various percentages of CMYK inks and to print these percentages, they have to be converted to raster dots. Spot inks do not need to be converted to raster dots to simulate a color, the inks are mixed into a single color (but when you need a percentage of a spot ink color, you need raster dots too).

[OssodiSeppia]

Thanks, Ton.  I think I'm not providing enough information.  I am talking about an ink jet printer with cyan, magenta, yellow and black inks.  Both Process and Spot colors will be converted by the printer driver.  Does the print driver treat the Spot and Process color shown in my original post differently?

[Ton Frederiks]

Generally the driver for ink jet printers converts the colors to RGB and the result to the inks in the printer (which can be different from the inks in a printing press).