How to Generate Code 39 requires print accuracy as well as a clear visual design. A label may look correct on screen but shift by a few millimetres on paper or produce a barcode that is difficult to scan. A reliable workflow separates design, data checking, test printing and scanning with the actual device.
The key principle
Internal symbologies are useful for SKUs, serial numbers and warehouse IDs. Choose a format that supports your character set and test it at the smallest planned print size.
Step-by-step workflow
- Measure the label or select a dimensional preset.
- Choose the barcode type and prepare a valid value.
- Add text, dynamic fields and an optional logo.
- Set sheet margins, gaps and the first available position.
- Run the quality check and correct any issues.
- Print one page at 100% scale and scan the code.
Practical example
Example: a sheet uses three columns of 63.5 mm labels. Do not assume that the preset matches every printer. Print a 100 mm ruler. If it measures 99 mm, enter a scale correction before checking the first and last columns.
Common mistakes
- printing with fit-to-page enabled
- removing the barcode quiet zone
- using a code that is too small or low resolution
- using an invalid check digit
- checking only the first spreadsheet row
- printing the full batch without a sample
Final checklist
- dimensions in millimetres
- 100% print scale
- valid barcode data
- strong contrast
- safe edge margin
- correct column mapping
- successful test scan
Tip: Save the project as JSON before a large print run. This preserves dimensions, elements and data mapping for later use.