
Beginning in 1937, Roy and Herb Brigham sought a way to eliminate tongue-bite, and coming to the conclusion that it was caused not by heat alone, but also by acids and tars in the smoke itself, sought to discover the perfect material for a smooth-drawing, unobtrusive, yet effective filter. After considerable experimentation they came up with two ideal materials - bamboo, and, much more readily available, rock maple.
With your Brigham pipe the filter can be used approximately 20-30 times with a dark brown filter indicating that its time to replace it (see below) and can also be cleaned, dried and re-used in a pinch. The rock maple filter uses no adhesives and can pass a pipe cleaner.