Bar Width Reduction
Bar Width Reduction (or BWR) is adjusting the barcode bars thickness to compensate for ink spread when printing.
Say if you draw with a marker pen on a very soft paper the ink will most likely spread and the line will become wider — the same might happen when you print, just not at that extent.
Ink spread, or “dot gain” or “press gain” may increase the width of the bars of the barcode and make it more difficult to scan. This is more common for traditional printing press, rather than office printers, but it is not just about printers. It also depends on ink, the substrate, the condition of the press, the room temperature and much more.
In order to avoid the scanning problems, you might need to compensate the ink spread by making the bars a little narrower, so they come to the normal thickness after printing and ink spreading.
Measuring the Bars
Although some shops and printers provide the bar reduction width, the best way to get the right number is to measure it yourself.
Start with no width adjustment and make a test print with the ink and paper you are going to use. Then measure the width of the printed bar and compare it with the reference with in the source file. The difference is what you need to compensate.
Adjusting the Bars Width
Say you printed a barcode, measured the bar and found out that the printed bar is 0.01 mm wider than the reference one. This means you need to make all the bars 0.01 mm narrower in order to compensate the press gain.
You can do this on the Appearance panel of our Barcode software, there is a special Bar width adjustment field there:
The reason it is called “adjustment” instead of “reduction” is to avoid the ambiguity of the latter. Adjustment clearly tells if we make the bars wider (positive values) or narrower (negative values), while reduction does the opposite which is not always intuitive.
So as the printed bars are 0.01 mm wider than we need, we should use -0.01mm width adjustment to compensate that:
The bars became a little thinner. It is barely visible to the naked eye, but if you reduce them even further, you will clearly see the effect:
The bars became much thinner and that’s exactly what the bar width adjustment does.
Here are some side notes that might be helpful:
- you can keep a record of BWR numbers you used for a specific press, ink and substrate, so you don’t have to re–test it for every job;
- you can use positive bar width adjustment to make the bars thicker, if needed;
- use a low power microscope or magnifier to measure the printed bars width.
More Barcode Tutorials
- Installation — how to install Barcode generator;
- License Activation — how to activate Barcode software with a license key.
- User Interface — Barcode user interface explained in details;
- Barcode Management — adding, renaming, cloning and deleting barcodes;
- Importing Barcodes — importing barcode images;
- Custom Texts — adding custom text elements to barcodes;
- Marks Panel — configuring border, margins and canvas of barcodes;
- Bar Width Reduction — adjusting barcodes to compensate for ink spread;
- Quiet Zone — making sure the barcodes can be scanned well.
- Making EAN–13 Barcodes — standard point–of–sale barcodes;
- EAN–13 Calculator — how to compute EAN–13 check digits.
- Making UPC–A Barcodes — learn to make UPC–A barcodes;
- Making UPC–E Barcodes — how to create UPC–E barcodes;
- UPC–A Calculator — compute check digits of UPC–A barcodes.
- NDC Barcodes — learn about NDC barcodes and how to make them;
- NDC Barcode Check Digit Calculator — how to compute NDC check digits.
- ISBN Barcode Generator — how to make ISBN barcodes;
- Transparent Barcodes — making barcodes with transparent background;
- PNG Barcodes — exporting barcodes to PNG format;
- Vector Barcodes — exporting barcodes to vector formats.
- Batch Processing — how to batch–convert text data to barcodes;
- Command Line Processing — command line barcode generation.