LaserWriter 12/640 PS: Text on envelopes smears

I am printing envelopes using a LaserWriter 12/640 PS printer and some of the text on the envelopes is getting smeared. How can I prevent this?
There will be some level of smearing when you print envelopes. Smearing occurs where the envelope is thickest, most commonly appears near the edge of the envelope. In order to minimize the amount of smearing, you should avoid printing close to the edge of the envelopes.
Published Date: Feb 20, 2012