I was just reading this post for the first time and do not seem to see anyone who quoted Scott Specialized definition of a cut square, so I'll post it now:
Quote:
"Very fine cut squares will have the design well centered within moderately large margins. The margins on 20th century cut squares should be at least 1/4 inch on the cut sides unless indicated otherwise. Cut squares of modern issues should show full tagging bars when they exist...Very fine cut squares (and entires) also will possess a fresh appearance and be free from defects...Precanceled cut squares must include the entire precancellation."
A lot of the earlier cut squares were intentionally cut "short" because album pages of that day did not accommodate the 1/4 inch margins on all sides, which is why some latitude is given to the older (19th century) cut square sizes as opposed to the modern 20th century counterparts.