In 1906 John Gamble as assingnor to A.G. Spalding patented a manufacturing process using male and female dies to molded dampened leather into a pre-formed pocket. Gamble thought the stitched perimeter seam of catchers mitts was a weak point and prone to ripping loose. His process also eliminated the sewn perimeter leather banding so common on catchers mitts of the day.
Below is a circa 1905 Reach 5A mitt showing the sewn perimeter banding joining the front section. 1906 Gamble patent below illustrating the molded face wrapping around to the laced back section From a 1909 Spalding catalog. Model 9-0 "Three-and-Out" with "Molded Face" circa 1909 Spalding 9-0 below with no perimeter leather banding 1940's Reach model A8 showing the molded face design.
Perimeter leather banding was not discarded after 1906. Many catchers mitts continued to use either a partial or tapered banding in conjunction with a molded face.