i'm using a samsung ML-2850ND (installed via samsung unified printer driver) laser printer to print to an envelope via open office word processor. by default, the printer assumes you are printing on a regular 'letter' size paper. i want to print on an a number 10 envelope, but my printer's properties does not have that in the selection for "paper size." it only has 'letter, legal, executive' etc and nothing for envelopes.

please help.