Why does a GS1 DataMatrix fail verification when I type parentheses into a regular generator?

In GS1 specifications, parentheses like (01) and (10) are for human-readable display only and must never be encoded as literal ASCII characters. ZPL Bench strips display parentheses, validates each Application Identifier, encodes the mandatory leading FNC1, and inserts ASCII 29 group separators after variable-length fields like (10) Lot.

What X-dimension (module size) should I use for a 203 DPI vs. 300 DPI thermal printer?

Always use an integer number of printer dots per module (such as 3, 4, or 6 dots). At 203 DPI (8 dpmm), a 4-dot module equals 0.500 mm (19.7 mil), ensuring every square cell aligns cleanly with the thermal printhead elements.

horizontal physical ruler · mm

3 mm layout guide

101.6 mm

813 × 1219 dots / 8 dpmm

Print checks

Encoding & geometry passed

1 encoded symbols / 0 warnings / 0 engine errors

Check Digit Status

PASS (GS1 AIs validated; start FNC1 encoded)

Validation is recalculated from the current source. Invalid identifiers do not produce a symbol.

Quiet Zone Clearance

PASS (Min margin: 9.0 mm)

Required L/R/T/B: 3.00 / 3.00 / 3.00 / 3.00 mm. Includes 3 mm layout clearance and symbology module minima.

left	9.00 mm / guide 6.00
right	84.38 mm / guide 81.38
top	51.75 mm / guide 48.75
bottom	92.38 mm / guide 89.38

Effective DPI	203.2
Dot pitch	0.1250 mm
Raster width	813 dots
Raster height	1219 dots

Technical specifications

Data Matrix / UDI specifications
Parameter	Specification
Symbology Standard	ISO/IEC 16022 Data Matrix ECC 200 with Reed–Solomon error correction
GS1 AI Support	(01) GTIN-14, (17) YYMMDD Expiry, (10) Batch/Lot, (21) Serial Number
Control Characters	Leading FNC1 codeword + ASCII 29 (<GS>) separator after variable-length AIs
Output Formats	Whole-dot aligned PDF, PNG, SVG, Raw .ZPL, and Avery/Thermal Batch Sheets

Parameter

Specification

Symbology Standard

ISO/IEC 16022 Data Matrix ECC 200 with Reed–Solomon error correction

GS1 AI Support

(01) GTIN-14, (17) YYMMDD Expiry, (10) Batch/Lot, (21) Serial Number

Control Characters

Leading FNC1 codeword + ASCII 29 (<GS>) separator after variable-length AIs

Output Formats

Whole-dot aligned PDF, PNG, SVG, Raw .ZPL, and Avery/Thermal Batch Sheets

Printer settings use 8 / 12 / 24 dots per millimeter. Nominal 203 / 300 / 600 DPI names correspond to effective 203.2 / 304.8 / 609.6 DPI device grids. Screen dimensions use the CSS reference of 96 px/in.

Operating procedure

Choose Plain ECC 200, GS1 DataMatrix, or a UDI-oriented AI layout sample.

Enter the identifier fields and match the symbol modules to whole printer dots.

Review FNC1, check digits, quiet zone, and bounds before exporting vector, raster, ZPL, or batch files.

Preflight validates supported identifiers and geometry; it does not certify scanner grades. Fix every red error before exporting.

Frequently asked questions

Tools

Pages

Navigation

Data Matrix ECC 200 & GS1 / UDI Barcode Generator

Print checks

Check Digit Status

Quiet Zone Clearance

X-Dimension

Printhead Dot Alignment

Element Bounds

Technical Specifications & Implementation Guide

Technical specifications

Operating procedure

Frequently asked questions