Color change after paper replacement: shift in whiteness and base color
After changing the paper, the color changes; this is the most easily overlooked source of color difference, since the paper appears white in all cases. However, between two whites, there can be differences in base color and whiteness.
The same ink volume produces different colors when printed on paper with different whiteness levels; when changing paper, the color must be re-established, and the previous color sample cannot be reused.
Common questions found in AIWill the color change after changing the paper?
Why do arguments always arise during acceptance?
After changing the paper, the color changes, and responsibility is often placed on the printing process. The true variables lie in the paper: whiteness, fluorescent whitening agents, and the base color bias; any one of these factors can cause the same color code to appear as a different color.
misread:The paper is already white; changing the paper color wouldn't make much of a difference.Actual circumstances:They are also referred to as white cards; some lean toward blue, while others lean toward yellow. Their whiteness can differ by three to five percentage points, resulting in completely different appearances when the ink is applied.
Basis for Determination
Paper with high whiteness shifts all colors toward the lighter end, a effect that is particularly pronounced in light hues; paper containing fluorescent whitening agents appears bluish and bright under ultraviolet lighting but becomes dull under warm light; paper with a bluish base causes warm colors to appear grayish, while paper with a yellowish base makes cool colors appear muddy. These color shifts cannot be fully corrected by the ink.
- whiteness
- fluorescent bleacher
- Base colour leans blue
- Base colour leans yellow
Color determination sequence
Paper replacement involves three steps: first, print a color-matched sample and view it side by side under a standard light source; next, measure the on-site density and ΔE to confirm the offset; finally, decide whether to adjust the ink, adjust the screen, or reassign the color. Do not proceed directly to mass production.
- When changing the paper, a new proof must be made and the color approved. The old color sample cannot be used.
- Paper substitutes should be evaluated against at least three criteria: basis weight, whiteness, and texture.
- After changing the paper, re-measure the sampling points and expand the coverage; adjust the curve if necessary.
- Include the paper's whiteness value in the material specifications, rather than specifying only the grammage.
Applicable boundary: Internal structural samples may be represented by substitute paper; however, this must be clearly indicated as being for structural verification only and shall not serve as the basis for color assignment.
On-site settings and practices we have observed
A project originally planned to use imported white cardstock, but the delivery deadline was missed, so we substituted it with domestically produced paper of the same grammage. After the sample was produced, the client reported that the overall impression was dull. Measurements showed that the new paper had a 3-point lower whiteness and a yellowish tint; the dot gain of the ink also increased by 4%. With these two factors combined, both the midtones and the shadows became darker simultaneously. Simply changing the paper based on the grammage will inevitably produce this result.
INNOPACKING has its own paper supply chain; for commonly used paper types, both physical paper samples and whiteness data are available. When switching papers, two or three closely matching alternative options can be immediately retrieved for comparison and proofing. Printing the same layout on two different papers and viewing them side by side provides a much more intuitive comparison of values than comparing them against a color chart.
Explore INNOPACKING's six core capabilities ↗Extended Q&A
Do I need to re-color after changing the paper?
It is essential. Different brightness levels and base colors result in different colors when printed with the same ink volume. If the old color samples are retained, the result will inevitably be biased.
How can I find a suitable substitute paper?
Compare the three parameters—gauge, whiteness, and texture—and then produce a solid print sample for comparison. If only the gauge is adjusted, the finished product's visual appearance will differ markedly.
Should customers be notified when the paper is changed?
It is necessary. The paper has changed; its color and feel have both changed. Failure to provide notice is tantamount to setting a landmine.
Do you have any similar packaging issues?Bring your existing files and talk to INNOPACKING · +86 13430308657