ASTM B-700

Standard Specification for Electrodeposited Coatings of Silver for Engineering Uses
Type 1 99.9% minimum
Type 2 99.0% minimum
Type 3 98.0% minimum
Grade A Matte
Grade B Bright. Obtained by use of brighteners in plating bath
Grade C Bright. Obtained by mechanical or chemical polishing
Grade D Semibright. Obtained by use of addition agents in plating bath
Class N No supplemental tarnish resistant treatment
Class S With supplemetal tarnish resistant treatment