The Dovetail Square is an excellent tool to help diagnose potential issues with your Dovetails before they become gaps in your assembled Joint. The Heart of this tool is the Sterling Dovetailing Ruler and was inspired by pattern makers squares that have been around for decades. Sterling designed the reduced size blade for woodworking and to fit commonly available squares. Sterling Tool Works was the first to make a reduced size blade longer for excellent diagnosing especially with “london” style dovetails where the pins meet to only a kerf. The length is 2-4 times longer than vintage tools for use with thicker stock or “gang cutting” 3/4? and thinner panels. The Sterling Dovetail Ruler, better by design and functionality.