Fixed pattern damage measures the damage in the finder pattern, quite zone, clock pattern and solid area segment regions. Pattern damage can be caused by an improper printer nozzle, a faulty thermal element, or physical damage to the barcode.

The following figure illustrates damage to the fixed pattern and the clock pattern:

The overall fixed pattern grade is the average of all grades. The final grade is the minimum of the finder pattern grade, quiet zone grade, clock pattern grade, solid area grade, or overall fixed pattern grade. The following list shows how overall fixed pattern damage is calculated.

  • A (4.0) if overall FPD grade = 4.0
  • B (3.0) if overall FPD grade ≥ 3.5
  • C (2.0) if overall FPD grade ≥ 3.0
  • D (1.0) if overall FPD grade ≥ 2.5
  • F (0.0) if overall FPD grade < 2.5

The following figure shows a Data Matrix code with a fixed pattern damage score of 2.4, which returns a grade of F and modulation grade of C.