My thanks to Jill Spreenberg-Robinson for permission to post this on my page! For reprint permission, please contact Jill.
To figure united inches, measure the length and width of the frame. Add these figures. Thus, an 8" x 10" frame = 18 united inches.
(Note: Unified inches is not to be confused with square inches! To figure square inches, multiply length times width.)
copyright 1999, Jill Spreenberg-Robinson. Contact her for reprint permission.