If you’re a hurried scrapbooker like I often am, there’s an easy way to mat your photos. Using this way, it doesn’t really matter what the size of your photo is. Simply lay your photo down on the piece of paper you want to use for your mat. Next, if you want to be precise, you can use a ruler, but I often eyeball this part.
Lay your photo next to a corner section of your piece of paper. Pull the photo away from the edge about 1/2″, or whatever size you want the mat to show around your picture. Keep your photo laying on the paper & mark the other two sides with a small pencil line Remove your photo, use your paper cutter to cut those edges you marked so that you will have the same width of mat all around your photo. Unless you want to get fancy, simply use double sided tape or a photo adhesive and attach your photo to the mat!