Spot color (for example, Pantone Matching System)
A premixed named ink (like a Pantone number) printed on its own plate, so the brand color aims at one agreed target instead of a four-ink guess.
See it
What it is
A spot color is a single premixed ink that runs on its own plate, instead of being simulated by dots of cyan, magenta, yellow, and black. Because the ink is mixed to a recipe before it reaches the press, everyone is aiming at one agreed target instead of rebuilding the color out of four screens every time. The Pantone Matching System is the common naming layer: '186 C' names a formula and a measured target on coated stock, which is why brand guidelines quote PMS numbers. Treat it as a specification, not a guarantee. Stock, ink batch, press condition, density, coating, and measurement tolerance all still move where the printed result lands.
Use spot when the color must be exact (brand identity, packaging), when it is outside the CMYK gamut (bright orange, deep navy, fluorescents), when you need metallic or neon, or when a one-color or two-color job is cheaper than full process. In a file, set the swatch to Spot, not Process, and keep the name byte-for-byte identical everywhere so it outputs one plate rather than three near-duplicates.
Gotcha: your monitor cannot show a spot color, it shows a CMYK guess. Judge from a physical Pantone book on the right paper (coated 'C' and uncoated 'U' chips of the same number look like different colors), check the bridge value before letting a digital press convert your spot to process, and remember each extra spot plate adds cost, which is why most jobs cap at one or two.
Ask AI for it
Prepare this artwork to output exactly two separations. Use [spot ink 1] and [spot ink 2] as named Pantone spot swatches, not process. If the design needs black, make black one of those two inks rather than adding a third plate. Use one identical swatch name per ink across every object so nothing outputs as a near-duplicate separation, and build every tint from those two inks only. Then list the final separations, flag every unintended process or spot swatch still lurking in the file, give the closest CMYK bridge values for the digital short-run version, and note any color four-color process cannot reach.