Printing Shipping Labels on USPS Website with Safari

--> EPIC FAIL

Analysis: for some reason, the printing function of safari is having trouble sending data to the printer, probably in very slow speed. The reason that I say it might be slow is that I actually got the first page of the labels after I cancelled the job and waited for a while. It might also be a problem processing later pages (#2 and 3).
Solution: Use firefox.