How to Print a #10 Window Envelope with Word Mail Merge

Open your document in desktop Word, navigate to the Mailings tab on the top ribbon, and click on Envelopes in the Create group.

In the Envelopes and Labels dialog box, click on Options. In the Envelope Options tab, select Size 10 from the Envelope size dropdown menu, and click OK.

Type the Delivery address and Return address into their respective text boxes.

Insert the blank envelope into your printer according to the feed icon, and click Print. Alternatively, click Add to Document to save the envelope setup as the first page of your Word file.

Set up your standard letter page and leave appropriate space for the recipient's address near the top left. The exact position depends on the specific window placement of your envelopes.

Go to the Mailings tab, select your recipient list, and click Insert Merge Field or Address Block in the spot you've designated for the window.

Print a test page of your letter, fold it as you would for mailing, and slide it into the window envelope to ensure the address is fully visible.

If the address is too high or too low, adjust the top or left margins or add blank spaces above the Address Block, then finish the Mail Merge to print your batch.