Sherwin, Inc.’s Dubl-Chek products are approved by governing agencies worldwide, including the US Government, ASME, ASTM, as well as the prime aerospace and military contractors and OEM’s. Dubl-Chek fluorescent penetrants are used widely in aerospace.

Through extensive raw and finished materials testing, Sherwin adheres to the highest possible quality assurance standards. Dubl-Chek products are uniform from batch to batch, and conformance certificates are always supplied free of charge.