The devices may use different inks, screening, colour gamuts and substrates. A digital mock-up can confirm layout and approximate appearance but is not automatically a contract colour proof for another printing process.

Not by itself. Monitor calibration, brightness, ambient light and colour-space conversion affect the display. Use screens for communication and approve colour through an agreed proof or physical standard.

Paper whiteness, tint, texture, absorbency, coating and opacity change reflected light and ink appearance. A colour approved on white coated stock may not match kraft, black or uncoated paper.

Yes. Gloss, matte and soft-touch films or coatings can change density, contrast, saturation and viewing-angle appearance. Approve colour with the intended final surface treatment when it is critical.

No. It identifies a target, but the formula, substrate, ink system, film thickness and finish affect the result. State whether a physical guide, measured sample or custom ink drawdown controls approval.

Ink-water balance, density, viscosity, temperature, substrate lots, press stability and drying can introduce variation. A process-control plan should define measurements, sampling and corrective action.

A conventional CMYK proof may not reproduce special ink, foil, opaque white, texture or gloss. Use process-specific swatches, drawdowns or production-representative trials for those effects.

Agree the illuminant, viewing condition, backing, instrument geometry, measurement mode and target values. Visual and instrumental evaluation should reference the same approved standard.

A golden sample may cover construction, print and finish together. A colour standard specifically controls colour and should be identified, protected, dated and linked to the production specification.

Approve the final substrate, print process, colour targets, proof type, special-colour evidence, surface finish, viewing condition, measurement plan and retained reference sample.