PicaJet

Reference Glossary

Colour separation

Colour separation is splitting full-color artwork into individual printing plates — CMYK process colors or named spot colors — each inked and printed separately, then combined on press.

Why it matters in a DAM

A DAM master intended for print must preserve separation-ready structure: the correct color mode and, for spot colors, named channels matching the exact Pantone reference. If someone flattens spot channels into a CMYK approximation before archiving the file, a later reprint loses the ability to output the true brand ink and can only simulate it with four-color process, which visibly shifts the actual color.

A worked example

CMYK process 4 plates — Cyan, Magenta, Yellow, Black — build full-color images from overlapping dots
Spot color plate 1 additional plate per named ink, e.g. a Pantone spot color, printed as a solid
DAM requirement Master file must retain named spot channels, not a flattened CMYK build

Common mistake

Flattening a file's named spot-color channels into their closest CMYK equivalents before archiving it in the DAM, permanently losing the data needed to print the true brand ink on a future reprint.

Colour separation is the step that turns a full-color image into the individual plates a printing press actually uses. In four-color process printing, that means splitting the artwork into Cyan, Magenta, Yellow, and Black (CMYK) plates, each printed in overlapping dot patterns that the eye blends into full color. When a design also specifies a named spot color — a logo printed in an exact Pantone ink rather than simulated from CMYK — that color gets its own separate plate, printed as a solid ink rather than a dot pattern.

For a DAM, this means the file’s internal color structure isn’t a cosmetic detail — it’s functional data that a prepress operator needs intact. A master file with a properly named spot-color channel tells the printer exactly which plate to run as a solid Pantone ink. If that channel gets collapsed into its nearest CMYK equivalent somewhere along the way — often to make a file look consistent across different software or during an export — the printer no longer has any way to reproduce the actual ink; they can only simulate an approximation.

This is a real risk specifically at the archiving stage: someone flattening a layered file for simplicity before storing it as the long-term DAM master removes information that can’t be recovered later. Keeping the true separation structure — CMYK plates plus any named spot channels — in the stored master is what lets a brand reprint years later with the same exact color, rather than a four-color guess at it.

Plate typeWhat it printsConsistency across vendors
CMYK process (4 plates)Full-color images built from overlapping dot patternsCan shift with press calibration and paper stock
Spot color plateOne named ink, printed as a solidSame physical ink everywhere it’s run

Frequently asked

What's the difference between CMYK separation and spot color separation?

CMYK separation builds any color from four process plates using overlapping dot patterns; spot color separation prints one specific pre-mixed ink as its own solid plate, used when an exact, consistent color match matters more than the flexibility of process printing.

Why would a file need both CMYK and spot color plates?

It's common for a piece to use CMYK for full-color photography while reserving a spot color plate for a logo or brand element that needs to match exactly, rather than being built from process dots that can shift slightly between print runs.

Does color separation happen automatically when a file is sent to print?

No — the file needs to already be structured correctly (correct color mode, named spot channels) before it reaches prepress; separation is a mechanical output of that structure, not something a printer can fix after the fact if the source file lacks it.

What happens if a spot color channel gets accidentally converted to CMYK?

The exact ink match is lost — the printer can only approximate the color using the four process inks, which typically looks visibly different from the true spot color, especially for brand colors like specific reds, oranges, or metallics that CMYK struggles to reproduce accurately.

Should a DAM store separation data as part of an asset's metadata?

At minimum, the color mode (CMYK, RGB, spot) and any named spot color references should be discoverable in the file itself or its metadata, so anyone pulling the asset for reprint knows what separation structure it was built with.

Is color separation relevant to digital-only assets?

No — separation is a print-specific concept tied to how ink is physically laid down on a press; digital assets destined only for screens use RGB color and don't get separated into plates.