Data integrity bug: Illustrator 30.3 changes CMYK swatch values after pasting clipboard bitmap image and reopening file
Product: Adobe Illustrator Desktop
Version tested: 30.3
Document color mode: CMYK
Issue type: Data integrity / color swatch value corruption
Summary:
Adobe Illustrator 30.3 reproducibly changes CMYK swatch values after a bitmap image from the system clipboard is pasted into a CMYK document. The issue appears after saving, closing, and reopening the .ai file.
Steps to reproduce:
- Create a new CMYK document in Illustrator 30.3.
- Create a CMYK swatch, for example C10 M10 Y10 K0.
- Paste any bitmap screenshot/image from the system clipboard into the document.
- Save the .ai file.
- Close the file.
- Reopen the file.
- Check the CMYK swatch value.
Actual result:
The CMYK swatch value changes from C10 M10 Y10 K0 to approximately C9.77 M9.77 Y9.77 K0 after reopening the file.
Expected result:
The CMYK swatch value should remain exactly C10 M10 Y10 K0. Pasting a bitmap image from the system clipboard should not modify existing CMYK swatch definitions.
Additional observations:
- The issue is reproducible in Illustrator 30.3.
- The issue is specifically triggered by bitmap images pasted from the system clipboard.
- If no clipboard bitmap image is pasted, the CMYK swatch value does not change.
- CMYK values such as 0%, 50%, and 100% do not appear to change.
- Values such as 10% change to approximately 9.77%, which suggests a possible unintended 8-bit quantization or percentage remapping.
- This is not just a display issue. The saved file reopens with changed CMYK swatch values.
Impact:
This is a serious print/prepress data integrity issue. It can silently alter exact CMYK swatch values, brand colors, and production colors in saved Illustrator files.
云飞
shared this idea
-
Doesn’t happens for me in 30.5.1 on Windows 10, pasting an RGB screenshot.
Both simple and global swatches retain their values.
My Color Settings are set to use Europe General Purpose 3. Check other parameters in the screenshot attached.
What settings do you use?
Please tell more. -
Rob
commented
You probably checked this, but by any chance did the color profile of the doc change after pasting in the bitmap image? I've noticed a bug where, regardless of the color profile that's been assigned, taking a screenshot and dragging it into the doc (directly from the Mac screenshot preview popup) changes the doc's color profile.
-
This bug is very serious and very easy to reproduce. It causes inconsistencies in the CMYK color values of a file before and after saving, affecting the consistency of output and printing color accuracy.
