I just read something very interesting. I thought that a new thread in the Luthiers' forum might be in order. Paul Everard Booker of the UK was, on October 18, 2005, granted US Patent # 6,956,158. This patent covers methods of determining the fret positions on a f*nned-fret fretboard. As well as a few related areas. It references the Novak patent, and it is demonstrated within this patent that the Novak patent results in an improper fret positions, except in the case where the strings are parallel. (This is a point that myself and many others, including some luthiers here, have previously discovered independently.) It describes two basic methods, with variations, to lay out f*nned frets. Each uses two reference scales to lay out the frets. The first of these methods results in fret positions with an acknowledged maximum of a one-cent intonation error; the second, while not stated as such, results in perfect positioning. The first method is somewhat strange, and is impressive if you're one to be impressed by geometry. The guy definitely has some intuition, and some analytical sense. The second method is, in my interpretation, an extension of the parenthetical mention in the Novak patent of a method of laying out two scales for the outer strings, and drawing lines between them. This part of the Novak patent however is not part of the "what is claimed" part of that patent. My interpretation of all this (IMO!) is that this patent reinforces the following points: - the Novak patent only covered the "converging to a point" method of creating a fan; - the Novak "converging to a point" fan produces bad intonation, and should not be used (except if the strings are parallel); - both of these patents cover specific methods to lay out the frets, cover a fingerboard produced by using the method, and the instrument containing the fingerboard. But - the basic idea of a multiscale instrument, with nonparallel frets, is not specifically patented by anyone, which makes sense since the concept has been in use for centuries. The Booker patent also covers jigs, and a nut-end string anchor. The Booker patent is here: http://patft1.uspto.gov/netacgi/nph...6,956,158.PN.&OS=PN/6,956,158&RS=PN/6,956,158 I found Paul Booker's website. He seems to have produced 1 1/2 basses so far, and gives lessons. http://www.btinternet.com/~paul.everard/equa/Splaybass.htm He also has some trussrod ideas, and has made a spreadsheet to calculate neck deflections based on profile and reinforcements. So what do you guys think?