What does quality control look like after a scanning project, and how much should I check?

Quality control (QC) is the step that proves a scanning project actually produced usable, trustworthy images, not just a pile of files. It happens after capture but before you destroy or retire originals, and it should be planned before the first page is scanned.

What QC checks

Good QC looks at more than “is there an image.” Reviewers typically confirm:

• Completeness — every page, side, and document was captured; nothing was skipped, stuck together, or cut off. Page and document counts match the source.
• Image quality — the image is in focus, properly exposed, fully deskewed and cropped, and free of streaks, shadows, or scanner artifacts. Color, resolution, and bit depth meet the target specification.
• Legibility — text and key details are readable, and any text-recognition (OCR) layer is reasonably accurate if it was promised.
• Technical accuracy — file format, naming, and folder structure follow the plan, and metadata correctly links each image to the right record.
• Integrity — files open without corruption and, where required, fixity values (checksums) confirm nothing changed in storage.

How much to check

There is no single mandated percentage. The right amount depends on the value and risk of the records and on how the work was produced.

• Sampling is standard for large, routine batches. A statistically meaningful sample drawn across operators, machines, and time lets you estimate the error rate without inspecting everything.
• Tiered review raises the rate for higher-stakes material — permanent, legal, vital, or hard-to-replace records often warrant close to 100% inspection.
• Trigger full review when a sample fails your acceptance threshold. Reject the batch, fix the root cause, and rescan rather than patching individual images.

Set the acceptance criteria and error tolerance in advance, in writing, so “good enough” is not decided case by case.

Document and decide

Record what you inspected, the defects found, and the disposition of each batch. That documentation supports any later decision to treat the digital copy as the official record and, where permitted, to dispose of paper originals. Aligning capture specifications and QC to recognized guidance keeps results defensible.

For broader context on planning capture and preservation, see the digitization and imaging topic hub.