With a variety of gages available for surface measurement, scratch pads are a method of the past for many manufacturers.
"Back in the day," as the saying goes, an experienced machinist would use a scratch pad and an educated fingernail to determine the surface quality of a part. Then, in the 1940s, E.J. Abbot of the University of Michigan developed a surface finish tester. Today, while scratch pads are still in occasional use, operators have a plethora of surface finish standards and parameters and a variety of gages to measure surfaces.