Sum of the external dimensions of a box; i.e., length, width and depth.

A simple art industry measurement that is the sum of the width plus the height. For example an image 24 inches wide by 36 inches high has a UI measure of 60 inches.

The addition of the dimensions of one length and one width of a lite of glass. Example: A window that is 24" wide and 72" high is 96 U.I.