File Prep Lab

FILEPREPLAB · PRINT PREPARATION

CMYK Total Ink Coverage (TAC) Checker

Add original CMYK percentages, compare a printer-specific TAC limit, inspect supported local CMYK TIFF samples, or read PDF page boxes. PDF TAC is not measured.

240.0% total ink coverage

Within the selected 300% reference limit. This is a numeric comparison, not print approval.

Inspect a supported local file

Supported ink samples: single-image, 8-bit, uncompressed, interleaved CMYK TIFF without alpha or spot channels; 20 MiB and 10 million pixels maximum. PDF support reads page boxes only (up to 50 pages). PDF TAC is unavailable. RGB images, compressed TIFF, BigTIFF, 16-bit, planar, alpha and multipage TIFF are rejected.

No selected file bytes are uploaded. The TIFF comparison uses original device-CMYK channel values without an ICC transform. PDF page boxes do not establish actual artwork bleed. No PDF/X-4 certification, transparency flattening, output simulation or overprint inspection is provided.

Verify Document Trim & 3mm Bleed Pixels →

Total area coverage is a channel sum

For one location, TAC = Cyan + Magenta + Yellow + Black. Each process channel ranges from 0% to 100%, so the numeric total can range from 0% to 400%. A 60/40/40/100 example totals 240%; four channels at 100% total 400%. A pass against a selected numeric threshold does not establish color accuracy or print readiness.

Choose the limit with your print provider

The default 300% and optional 240% examples are references for discussion, not universal ISO 12647-2 or Ghent Workgroup mandates. Paper, coating, ink, drying and profile conditions change the appropriate limit. A rich-black recipe can change appearance between processes. Black-only small type and overprinting should follow the provider’s instructions; no fixed 14-point rule is enforced here.

What the local TIFF reader measures

The restricted reader examines every original 8-bit CMYK pixel in a supported TIFF. It reports maximum and average sum and the number of pixels strictly above the selected threshold. Samples are mapped from byte values 0–255 to 0–100%. This quantization means a nominal percentage may not be represented exactly. An embedded ICC profile is reported but not applied.

Unsupported files fail with a reason; they are not silently rendered as RGB. Compressed or planar TIFF, 16-bit samples, spot channels, alpha, multipage images and BigTIFF are outside this implementation. Export a separate uncompressed 8-bit CMYK TIFF from your color-managed application when this restricted numeric check is useful.

Why PDF ink coverage remains unavailable

A PDF can contain vector process color, spot color, ICC-based objects, transparency, masks, patterns, blend modes and overprint. A browser RGB preview does not retain those original separations. Reading page boxes is useful for geometry but cannot prove actual background artwork reaches bleed or establish the page’s total ink. This page makes no PDF/X-4 compliance claim.

Use a color-managed separation preview and preflight tool, then confirm the result against the printer’s output condition. Adobe Acrobat Output Preview describes its separation and total-area-coverage workflow. This tool does not replace that analysis or a print proof.