Have you printed Fedex or UPS shipping labels on your laser printer and the toner is flaking off or easy to rub off? The knee jerk reaction would be to blame the label stock. The most common labels to use for FedEx, UPS or USPS labels are the full sheet ML-0100 labels or the half sheet ML-0200 labels. If you're using these labels, and having these types of problems, the first solution should be to change the media to "Labels" or if that's not one of the choices, the thickest paper available, in the printer properties.
The easiest way to get to the printer properties is when you're in the label template document in Microsoft Word. Simply go to print the document by either presssing the Ctrl-p key combination or click on the File menu and select Print. Under the printer that you're using, click on "Printer Properties".
You'll get the Printer Properties for your particular printer that is similar to the Brother printer below. Click on the drop down menu for "Media Type" and choose "Label"
The printing speed will not be as fast as before, but the toner will have a much better chance to adhere to the label paper.