On all the HP laserjet
printers I have worked with, which is basicly any non-color Laserjet released in the last 6 years, each tray has 2 settings, one for paper size
) and one for paper type
, Letterhead, Preprinted
This is used by the printer to determine what tray to print from when receiving a printjob, but it also tells the printer to lower or raise its fuser temperature.
The temperature is lowered a bit for transparancies and raised for rough, thicker paper.
BTW, to get toner out of clothing, wash it out with cold water. Don't put it in the washing machine, the warm water will fuse the toner to your clothes just like a laser printer does to paper.
Using too low a fuser temperture leads to improper fusing, where the toner can be wiped off the paper.
When the temperature is to high, the paper will curl heavily, possibly burn a bit and in the case of transparancies, melt and wrap around the fuser.