Several Avery postcards are 4 per sheet, 4-1/4x5-1/2 inches. The different numbers represent different colors, textures, pack sizes or printer compatibility (inkjet or laser or both), but the 4/sheet postcards share the same template.
You can design these using the 8387 template in Avery Design & Print Online.
You can also use a template built into Microsoft Word or download an Avery 8387 template for Word, Photoshop, Illustrator, InDesign or Pages.
Here's some information on recommended printer settings.
If you want more information about a specific Avery product, search for the product number on avery.com.
We also offer 4" x 6" Postcards.