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Print Production Tool

QR Dot Gain Tolerance Checker

Check whether a module size survives your printer's dot gain and misregistration, and find the minimum safe module size if it does not. All values are computed from the numbers you enter.

1. Enter print measurements (mm)

Rule used: total spread = dot gain + misregistration. Pass when total spread ≤ 25% of the module size. Minimum safe module = total spread ÷ 0.25. Effective dark module = module + 2 × dot gain; effective light module = module − 2 × dot gain.

Result
Verdict
PASS
total spread 0.11 mm = 22.0% of module
Minimum safe module0.44 mm
Effective dark module0.66 mm
Effective light module0.34 mm

This module size has enough headroom for the entered dot gain and misregistration.

Small Codes Are Where Dot Gain Bites

A large poster code can absorb a tenth of a millimetre of ink spread without anyone noticing. A tiny code on a label cannot: the same spread is a large fraction of each module, the light gaps close up, and the scanner sees a dark blur. That is why dot gain is a print-production check, not a design preference — it depends on the actual printer, stock, and ink, and it must be checked at the actual printed size.

If the check fails

The most reliable fix is a larger code. If the layout cannot grow, reduce ink density, choose a smoother, less absorbent stock, or move the job to a printer with tighter registration. Always confirm with a printed proof scanned on two different phones.

Frequently Asked Questions

What is dot gain?

Dot gain is the spread of ink beyond its intended area as it soaks into stock or squashes under press pressure. Dark modules grow and light modules shrink, so a code printed with heavy dot gain can lose its light gaps even though the artwork was correct.

Why is the limit 25% of the module size?

This tool uses a conservative production rule: total spread (dot gain plus misregistration) should stay at or below one quarter of a module. Beyond that, light modules narrow enough that scanners start misreading them, especially on small codes.

How do I measure dot gain for my printer?

Print a test patch with known module sizes, measure the printed modules with a loupe or scanner, and subtract the intended size. Your printer or press vendor can also supply a dot-gain figure for a given stock and ink.

What if my code fails this check?

Increase the module size (print the code larger), switch to a smoother stock with less ink spread, reduce ink density, or use a printer with tighter registration. Do not just hope the scanner compensates — it may on one phone and not on another.