Once the card has been graded it will be slabbed. The process is supposed to be handled by the graders without knowing who the customer is, so there is no "bias."
Check out this video about the grading process! I just packed up some cards and I will be sending to PSA in the morning. I hope they come back 10's!!
http://www.youtube.com/watch?v=I0Mqn62_LlQ