Load Envelopes You can print on plain paper envelopes in 4 1/8 × 9 1/2 inch (#10) (105 × 241 mm) size. 1. Open the paper support and pull up the extensions. 2. Pull out the output tray extensions, and flip up the paper stopper. 3. Squeeze the edge guide and slide it left. Note:If the feeder guard is in the way, flip it forward. 4. Load up to 10 envelopes against the right side and beneath the tab. Load them printable side up and flap edge left. Tip:Press each envelope flat before loading it or load one envelope at a time. 5. Slide the edge guide to the edge of the envelopes, but not too tightly. See also: Load Paper for Documents Load Paper for Photos