If you have Word 2010 or 2013, you don't need any additional software to print directly onto envelopes. Whether you want a single envelope with an address printed on it, a branded envelope displaying your logo or a design, or an entire pack of envelopes with only your return address for hand-addressing, Word can print using any printer that supports feeding blank envelopes. There's no need to adjust the margins using trial and error and throw out envelope after envelope -- Word's envelope creator includes formats for every common envelope size.
Click "Envelopes" in the Create section of the Mailings tab to start a new envelope. Fill in the delivery and return addresses.
Press "Options" to change the direction in which you feed envelopes into your printer on the "Printing Options" tab. Word selects a default based on your printer model, but if you already tried the suggested method and it didn't work, pick the correct orientation.
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If your printer uses an alternate tray to feed envelopes, select it in the Feed from drop-down menu.
Pick an envelope size or change the font settings for the addresses on the "Envelope Options" tab. To reposition the addresses on the envelope, change the from left and from top settings. For example, if you know your printer cuts off the left side of the page and you feed envelopes horizontally, use a high from left setting on the return address.
Click "Add to Document" to create the envelope. If you entered a new return address, Word asks whether to save the address for future envelopes.
To print the envelope immediately instead of editing it further or saving it, press "Print" instead of "Add to Document."
Choose "Pictures" or "Online Pictures" ("Clip Art" in Word 2010) on the Insert tab to place an image on the envelope. After inserting an image, shrink it with the handles on its corners until it fits on the envelope. To position the image, change its wrapping: right-click the image, choose "Wrap Text, " pick "Tight" and then drag it into place. After you place an image, click on the delivery address to make sure the top of the text box doesn't fall behind the image.
After you have the envelope laid out to your liking, print or save it from the File menu as you would any other document. You don't need to change the paper size setting on the Print tab -- Word already set this option when you created the envelope.