Each standard stretcher bar measures 11/16"x 1-9/16" (1.75cm x 4.03cm) and feature a tongue-and-groove design. FREDRIX reduces waste and improves stability with the use of finger joints and all bars are knot-free. The wood is sourced from managed sustainable forests primarily in the North Western U.S. They are kiln-dried and precision cut using state-of-the-art computer driven milling machines to ensure a smooth and tight fit.