7. Make sure the printer is on-line and start your print operation.Printing On EnvelopesYou can stack up to 15 envelopes in the sheet feeder. Before printing onenvelopes, you need to turn on the envelope mode.Use only Commercial number 10 envelopes, which are 9 1/2 x 4 1/8inches.NOTE: Do not leave paper stacked in the printer for long periods of time;longer sheets of paper may become bent or curled over time. This maycause the paper to misfeed or jam.CAUTION: Some envelopes are not recommended because they maycause jams or smears or may damage your printer: Envelopes with windows, metal clasps, holes, perforations, cutouts,double flaps, or peel-off sealing strips. Envelopes that are specially or deeply embossed. Envelopes with letters enclosed.