Bar codes are printing with variable line width. Part of the bar code prints with thicker lines.
This is caused by another object overlapping the bar code object. Even if this object has a white background and cannot be seen on screen it can cause variable line width on bar codes. This is especially true if you are using the Nice Label software. (See Below)To fix this issue, remove the overlapping objects from bar code objects. Click on an object to reveal the object boundaries.
Bar codes are identified by the driver so that quality compensation can be applied. This compensation is necessary to provide better scanning bar codes. If overlapping objects are present, the bar code cannot be properly identified in those overlapping areas. The compensation cannot be applied resulting in thicker lines printing in the overlapping areas.