I have uploaded documents to print to the MyPrintCenter (print.uw.edu) and they aren't showing up on the printing station
Answer
In order to get documents to appear on the printing station monitor, you must first upload the document to print.uw.edu, as indicated by the question. Once that is complete, log into the printing station and type in your UW netid, not your student number. Your netid is the portion of your UW email address prior to @uw.edu.
Example: If Harry the Husky had a UW student number of 123456789 and a UW email of HarryHusky@uw.edu, he would sign into the printing station by first typing in "HarryHusky", then swiping his Husky ID card. Harry will now be able to find his printing documents on the printing station.