Why Are Margins Important? If you are not covering up any part of your cover or art, then they are not important. If a portion is to be covered, then it is important because the information on margins is used to determine how your item is positioned in the frame. It is also important because covering up a portion of the image can lower the cost of your frame.
Looking at the art, we see that there are margins on all four sides that may be covered. The most important is the 11/16" bottom margin as we will see below.
This is the back of the frame package with the art sitting in a cutout sink mat behind the double matting.
I have moved the art sideways to show that gap between the bottom shelf of the sink mat and the double matting.
I have turned the art around so you can see that the bottom of the double matting lines up with the bottom margin of the art. I size this gap based on the bottom margin
Here is the art showing all the margins. The bottom margin is 11/16", the top is 3/4", the left side is 3/4" and the right margin is 11/16". The overall size of the art is 11 1/2" by 16 1/2". The displayed area of the art is 10 1/16" by 15 1/16". Pricing is based on the displayed area, not the overall area. The overall area is 28 United Inches (UI), the displayed area is 25 1/8" UI.