Bluing winding checks* is tricky. It requires near surgical cleanliness and excellent timing. We have been bluing checks for the better part of 15 years and now offer this service to you. For those unfamiliar with what "bluing" is, bluing is a chemical treatment of, in this case nickel silver checks, that turns them from a bright chrome like finish to a dark charcoal almost black finish. All checks will receive an enamel finish after bluing to protect the ferrule.
*Price is per individual winding check.