1992
AL#30 p.44   BRB3 p.204            read this article
Tim Earls                                                                                           

▪ Multiple radius fingerboards revisited. Also called conical fretboards. Earls strives to put the design process into the hands of Joe Guitar maker using “barnyard” geometry. Seems to work. The article also contains a description of the Warmoth multiradius fretboard, which has become sort of the industry leader.