Why CMYK runs out of road

Process printing builds every colour from halftone mixes of cyan, magenta, yellow and black. The reachable set (the gamut) covers most work, but saturated oranges, greens, violets and many corporate brand colours sit outside it: no CMYK percentage combination lands on them. When a job's whole identity is one of those colours, "close" is a complaint waiting to happen.

Option one: a spot ink

A spot colour is a physically mixed ink, matched to a swatch (Pantone's matching system being the dominant commercial library), running in its own press unit. It hits the target exactly and repeats reliably, which is why brand guidelines specify spot references. The costs are structural: each spot adds a plate, a press unit, ink you may have to buy in job-lot quantities, and a wash-up between jobs. One or two spots on a long corporate run is routine; five spots on a short run is a quote you will not enjoy (how the pricing works).

Option two: extended gamut (CMYK-OGV)

Extended-gamut printing adds orange, green and violet process inks to the standard four, making a seven-colour process set that stays fixed on the press. Brand colours are then built from those seven, instead of mixing a bucket per colour. Pantone's own extended-gamut material claims the seven-ink process achieves an acceptable visual match for roughly 90 per cent of its solid colour library; that is Pantone's figure about Pantone's product, so treat it as the vendor's claim, but the mechanism is sound and the packaging and label sectors have adopted it widely. The win is operational: no ink changes and no wash-ups between jobs, which is exactly what gang-run label and carton production wants. The trade-off: a built colour is a very good match, not a mixed ink's exact one, and the last few per cent of the library (metallics, fluorescents, the extreme corners) still needs real special inks.

And retire Hexachrome from your vocabulary

The old six-colour Hexachrome system (CMYK plus orange and green) was Pantone's 1990s answer to the same problem and has been discontinued for years; Pantone's current education pages describe extended gamut, not Hexachrome. The legacy post this page replaces recommended it; specifying it today would date a brief instantly. This correction is a fair sample of why this masthead rewrites rather than republishes.

Where the standards fit: ISO 12647-2 and G7 are not rivals

Two labels appear on Australian printers' capability statements, and they describe the same discipline from different angles. ISO 12647-2 is the international process-control standard for offset: it defines the measurable targets (ink colour values, tone reproduction) a compliant sheet should hit. GRACoL and the G7 methodology, published by Idealliance, are the dominant calibration method a shop uses to get its presses and proofs to behave that way, built around grey balance. A shop claiming "G7 Master" and a shop claiming "ISO 12647-2 compliant" are both telling you their colour is measured against a public target rather than eyeballed; that is the substance of the claim to check (our quality explainer covers how to check it).

The buyer's decision, compressed

  • Brand colour inside CMYK gamut: print process, manage it to standard, save the money.
  • One critical out-of-gamut brand colour, recurring long runs: a spot ink earns its unit.
  • Many colours, versioned packaging/labels, frequent job changes: extended gamut is built for exactly this; ask your converter what their fixed ink set achieves on your specific colours, measured, before committing.
  • Mirror metallic or fluoro: no process build will do it; that is foil or specialty ink territory.