In one sentence, describe what the following article is about:

When the photo looks right, choose "Print" from the File menu. You can choose both 3x5 and 4x6 in addition to other sizes. You can choose a standard border or you can add matting.

Summary:
Place the inks and photo paper recommended by your printer manufacturer into your printer. Open iPhoto and open the photo that you want to print. Edit the photo as needed. Click on "Print Size" in the Printer window to choose a size for your photo. Choose your layout on the left side of the Print menu. Click "Print" to print your photo.