The client approves colour on a screen, the printer approves it on a sheet, and the shopper sees the pack on a shelf under cold retail light. The gap between those three points is physics, not somebody’s mistake. Colour management exists to make that gap predictable and keep it inside a tolerance.
What actually moves colour
- Substrate: board whiteness and shade, film transparency and metallised stock all change the same ink.
- Process: offset, flexo and digital differ in gamut and dot gain.
- Ink film thickness and the sequence in which colours are laid down.
- Finishing: matt varnish mutes saturation, gloss lifts it, foil shifts how neighbouring areas read.
- Viewing conditions: sheets can only be compared under standard D50 lighting.
Spot or process
Key brand colours belong in spot inks: they hold better across a run and depend less on ink balance. But every extra print unit costs money. The prepress job is to work out where a spot colour is mandatory — logo, signature background — and where process build with dE control is entirely safe.
How to lock the agreement
- Define target Lab values and a dE tolerance for every critical element.
- Agree the print profile for the specific substrate and process pairing.
- Produce a proof bound to that profile; it becomes the reference for approval.
- Build control strips into the artwork so deviation is measured, not debated.
- Measure colour at make-ready and sign off a reference sheet.
What it buys you
Once colour is written as numbers and a tolerance, press approval stops being an argument about taste: any deviation is checked with a spectrophotometer. For a range of SKUs it matters twice as much — packs from one family must look like one family, even when printed at different times, on different substrates and in different plants.