Glazing Jack

Also called a glazing machine, a glazing jack is a tool used to polish and finish leather, built around a solid glass cylinder, roughly two inches across and six inches long, mounted on an arm that strokes rapidly back and forth across the leather's surface under heavy pressure while the operator moves the hide beneath it. The repeated stroking compresses and smooths the leather's surface and raises its color, and the friction's heat can further darken and harden an aniline-dyed finish; because no pigment is applied over the leather, its natural porous structure stays visible beneath the glaze. Glazing is slow, labor-intensive work, so it is usually reserved for finer or more exotic leathers, such as reptile skins.