Key question
Why does the same colour look different on different paper?
Printing ink is usually translucent: the paper shows through and blends with it. Paper shade, surface texture and absorbency alter brightness, saturation and sharpness. Knowing this allows you to plan colours that suit the material, avoiding any surprises when printing.
Learning objective: You can explain how paper affects a printing colour and verify colours using colour swatches, proofs, and press proofs.
Paper is always the fifth colour.
5.1 / Colour Meets Paper
Printing ink is more transparent than you think.
Four terms explain why colour appears so differently on paper:
01
CMYK
Four process colours are printed as halftones; the blended shades only appear in the eye.
02
Spot colour
A pre-mixed colour, such as Pantone or HKS; consistent and often more vibrant.
03
Paper clay
Every colour blends with the paper: on yellowish paper, blue takes on a slightly greenish hue.
04
Dot gain
Halftone dots expand during printing; this happens more on absorbent paper, causing images to appear darker.
Coated papers keep the ink on the surface: colours look rich, images sharp. Uncoated papers absorb the ink, making shades flatter and midtones darker. The "Pipeline & Workflow" course shows you how to take this into account using colour profiles and during PDF export.
Paper always plays a part.
5.2 / Secure colour
Colour only truly becomes definite once on paper.
Screens emit light, whereas paper reflects it. For this reason, no monitor can provide a truly reliable preview. Colours are accurately verified using printed swatch books, a colour proof, or a press proof on the actual paper.
Pantone colour guides are available for coated (C) and uncoated (U) paper. The same colour number looks significantly different in each guide. Always choose from the guide that matches your paper.
01
Colour swatch
Printed colour swatches show how a colour looks on coated or uncoated paper.
02
Proof
A colour-accurate contract proof simulates the print result in accordance with the standard.
03
Proof
A proof print on the actual machine using the real paper.
Approve on paper, not on screen.
5.3 / Paper changes colour
Same colour value, different effect.
On coloured paper, printing ink acts like a coloured film: light colours almost disappear, while dark ones remain visible. On brown kraft paper, you therefore need bold, dark shades or an opaque colour such as screen-printed white.
Light shades often appear pale on uncoated paper; consciously choose slightly bolder tones from the uncoated swatch book. Always allow for a proof on the actual material for key brand colours.
Light colours need light paper.
Exercise
Test colour
Task: Test the 'Kornfeld' brand colours on three papers.
STEP 1
Choose two brand colours and locate them in the C and U swatch books.
STEP 2
Print both colours onto white, off-white and brown paper.
STEP 3
Compare the samples in daylight and note the differences.
STEP 4
Decide which colour is used on which paper.
Evaluation: Which colour has changed the most, and what does this mean for the design?