Blackfast 183 will darken bright brass surfaces to a dark brown. The bath should be maintained at a temperature range 35-40ºC for the best results. At lower temperatures, the process is slower and the recommended immersion time of 5 minutes is exceeded.
On removal from the solution, the brass is allowed to dry then lightly abraded to remove some of the coating on proud surfaces. What remains will be within the crevices and surface of the brass revealing an antiqued surface.