The most popular scale to go with a given gauge was often arrived at through the following roundabout process: German artisans would take strips of metal of standard metric size to construct their products from blueprints dimensioned in inches. "Four mm to the foot" yielded the 1:76.2 size of the British "OO scale", which is anomalously used on the standard HO/OO scale (16.5 mm gauge from 3.5 mm/foot scale) tracks, because early electric motors weren't available commercially in smaller sizes. Today, most scale sizes are internationally standardized, with the notable exceptions of O scale and N scale.