Surface Area Measuring Test for Grained Aluminum Lithographic Plates.

A new procedure and apparatus for measuring the surface area of grained aluminum litho plates has been developed. The process is rapid, easy to perform, and can be employed for fundamental investigations involving graining, The test involves barrier layer anodizing in a tartaric acid electrolyte following certain prescribed pretreatment steps. The increase in surface area due to graining is related to the ampere-seconds used to form the anodic oxide.