In original Fig.of Hudleston (1973) are shown radiating lines beginning from origin designated alphabetically from A to F. Also shown are five slightly curved lines numbered 1 to 5. These two sets of lines intersect in 30 points which Hudleston considers as 30 "ideal" shapes each of Which has a particular b3 /b1 ratio. These ideal shapes have been reproduced in another fig. These ideal shapes can be reproduced on a Perspex sheet and any fold shape in profile irrespective of its size can be viewed through it and matched with one or a combination of two shapes and noted in the field diary or notebook as 3C or E4. This is the visual method of harmonic analysis, in which case the first two coefficients of a fold shape can be simply calculated in terms of one or two of the standard 30 shapes.