When using the BarcodeMaker add-in with Word 2007 or later, a barcode is created and displays on-screen properly, but when printed, the barcode is unreadable by a barcode scanner.
In Word, click the generated barcode so it is selected (a dotted-line bounding box appears around it).
Note: If the barcode will not select when clicked, click the Add-Ins tab, click the "Create ActiveX Barcode" button, then click Undo in the Quick Access Toolbar (or type Ctrl-Z). The barcode should now be selectable.
Click the handle (small square dot) on the right side of the bounding box, then drag it to the right a small amount. This expands the box so the barcode will print all the bars needed for a valid barcode. It may be necessary to expand the bounding box more than once to determine a sufficient amount of expansion.