The Vault
Troubleshooting guide
Why is my offset press scumming — ink showing up in the non-image (blank) areas of the sheet?
Posted by the SuperPrinters team · 7/26/2026
Ink appears as a dirty tint, film, or smudge in areas that should print clean and white, and it typically gets worse as the run continues or the press warms up. Most often caused by ink/water balance running too dry — not enough fountain solution reaching the plate to keep non-image areas desensitized, among other possible causes — a full step-by-step diagnostic and fix follows below.
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