No. 10 Envelope (Approximately 9 1/2 x 4 1/8 inches)

1. Use this size of envelope for standard business letters.
2. Check the inside address on the letter with the address on the envelope to be sure they correspond.
3. Be sure that the letter is properly signed.
4. Place the letter face-up on the desk.
5. Fold slightly less than one-third of the letter up toward the top edge of the sheet. With the edges even at the sides, crease the fold.
6. Fold the top downward so that the top edge of the letterhead is within one-half inch of the bottom fold. With the edges even at the sides, crease the fold.
7. Insert into the envelope with the last crease toward the bottom of the envelope.

Small Business Envelope (Approximately 6 1/2 x 3 5/8 inches)

1. This size envelope is used rarely in a business office, but it is an acceptable size.
2. Check the inside address on the letter with the address on the envelope to be sure they correspond.
3. Be sure that the letter is properly signed.
4. Place the letter face-up on the desk.
5. Fold the letter from the bottom to within one-half inch of the top edge. With the edges even at the sides, crease the fold.
6. Fold from right to left, one-third of the sheet width.
7. Fold from left to right, to one-half inch of the last crease.
8. Insert into envelope with last creased edge inserted first.

No. 10 Window Envelopes (Inserting 8 1/2 x 11 inch paper)

1. Place the sheet facedown, top toward you. Fold the upper one-third down toward you.
2. Fold the lower one-third of the sheet up so that the address will be on the outside.
3. Insert the sheet in the envelope with the last crease at the bottom so the inside address shows through the window.
4. Check to see that the ZIP Code number shows through the window.