Unabel to Scan Barcode Printed with Font
This troubleshooting procedure assumes the barcode font is installed and can be printed from an application (such as WordPad in Windows). If the font does not print from an application, refer to the Font Installation Procedures or TrueType font problems in Windows.
Barcodes are designed to be read by machines, specifically barcode scanners, which interpret the pattern of bars and spaces to extract data. When you print a barcode using a font, it essentially treats the barcode as any other text, rather than encoding it in the specific pattern required for scanning.
Fonts are designed for human readability and aesthetics, not for encoding machine-readable data like barcodes. As a result, the barcode printed with a font might lack the necessary precision in bar width, spacing, and other characteristics that are critical for accurate scanning.
Additionally, barcode scanners are programmed to recognize and interpret barcodes according to specific symbology standards (such as UPC, Code 39, QR code, etc.). Printing a barcode using a font doesn't adhere to these standards, making it difficult or impossible for scanners to interpret the information correctly.
In essence, using a font to print a barcode results in a visual representation that resembles a barcode, but lacks the technical specifications required for machine scanning and interpretation. Therefore, scanners are unable to read barcodes printed with fonts.
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The most common cause for a barcode font failing to scan is a missing or incorrect start, stop or check digit. All barcode fonts require a special start character, a stop character and most require a calculated check digit. Make sure the required format is being used to print the barcode fonts.
Self-checking fonts like Code 39 and Codabar can easily be entered from the keyboard with the start/stop characters because a check digit is not required.
For example to encode 123945 in a Code 39 barcode font, enter *123945* in the application and select the Code 39 font for that text. Some examples of encoding Codabar and Code 39 are listed in this chart:
Because the checksum calculation can be complicated, IDAutomation provides several Font Encoders to calculate these characters. A correct barcode font contains a start character, data characters, a check digit, and a stop character. All must be entered in this order to create a correct barcode.
The chart below contains a few examples of those fonts requiring check digits. The “text required in barcode font” column may be reproduced with any data in the online font encoder.
Some demo and sample version fonts may be missing characters. Make sure all demo and sample fonts are removed before installing the fully functional versions. If the font name contains the letter “S”, it is usually a sample or demo font.
Code 128 and Interleaved 2 of 5 fonts distributed from July 2003 to January 2004 sometimes appear in the font list with the @ sign in front of them. Choose the barcode fonts without the “@” sign at the beginning of the font name because the font names with the “@” sign may cause errors.
Browse to IDAutomation’s Online Barcode Creator, select the correct symbology, and enter some data to encode. Print it out on the same printer. Does it scan? If not, the problem is usually with the scanner. Make sure the symbology is enabled in the scanner for the barcode being scanned; check the minimum and maximum character settings; also check the scanner settings for that symbology. Check the barcode scanner manual for reference. Most barcode scanner manuals have test barcodes in them; try scanning those of the same symbology to make sure they scan.
Try printing the barcode font at different point sizes. Not all barcode scanners are the same; some lack the ability to scan all types and sizes of barcodes. Some scanners have a narrow reading width and cannot read long barcodes, while others cannot read small barcodes. Review the readme file within the font distribution ZIP file for the ranges of point sizes that can be used. Generally, 12 points is a good starting point. If that does not work, use 16 or 24 points.
All UPC and EAN fonts should be printed at 22 points or greater.
If the barcode appears to be truncated, increase the height and width of the field the font is displayed in so there is extra white space before and after the resulting barcode. Most barcodes require a white space around the printed symbol that is at least 10 times the most narrow bar in the barcode.
Check the print quality and DPI of the printer. Thermal printers that are 203dpi or less can produce poor quality problems if not used properly.
Make sure the material the barcode is printed on has the proper contrast. Normally, the barcode should be black and the background white. Using other colors will usually cause poor scanning conditions. Also, make sure the material is not too glossy or the scanner light may reflect and will not properly read the barcode.