rim of upper material extending around the featherline of its last, used to outseam it to the bottom
In welted constructions, the flange is the welt table created by inseaming a projecting welt to the upper.
In stitchdown construction, the flange is the part of the upper turned out at the featherline.
In Blake Rapid construction, the flange is the rim of the midsole projecting out past the upper under the featherline.