Why grade?
A scanner that reads a code tells you only that one device could read it. A grade predicts how well any scanner will read it.
The parameters
Standards measure contrast, modulation, fixed-pattern damage, uniformity and unused error correction, among others. The lowest parameter sets the overall grade.
Common causes of low grades
Low contrast between ink and background, inconsistent dot size, a damaged finder pattern and insufficient quiet zone.
Improving results
Stabilise product handling, keep printheads and lenses clean, choose a larger cell size, and print on a plain, light patch.
