Because every piece of oboe cane appears much wider after folding than when straightened out, the Template width of a Machine-Shaper in no way resembles that of the finished reed, but is always considerably narrower than the cane from a hand Shaper-Tip. Furthermore, the results vary grossly according to the time for which the cane is soaked. The divergence anyhow increases with the metal width, but reduces as the shape grows narrower. So the very pattern of each shape can vary.
This means that the catalogue widths specified to date are highly misleading. The true widths (in different regions) of the cane that emerges need to be researched before purchase, or much time and money will be wasted.
The conversion formula has been generously provided by Udo Heng of Reeds 'n Stuff, and is quoted in Understanding the Oboe Reed, where Chapter 8C explains in reassuring detail the numerous challenges and their routine solutions. The Oboe-Shop.de provides a helpful interactive table to sort the results of the models they sell, according to the relevant region of the shape, although this still describes the Metal Widths.
The Tables below have been assembled from the vast catalogue of A. Hörtnagl, and are offered to assist oboists in their researches. They will be most easily read on a large monitor. The products stocked by each supplier are colour-coded for clarity, and listed together in order of increasing width. The 'True' Cane Widths converted in the right-hand columns are those which should result from a Machine-Shaper Template when the cane is soaked just until it sinks in tepid water, but after later folding. Many players prefer, however, to soak for a shorter time, so, inevitably, their wider results will vary considerably. A complete description of the required controls and recommended variations according to soaking technique is detailed in Understanding the Oboe Reed.
Fortunately all Templates may be exchanged between the machines of Adolf Hörtnagl, Reeds 'n Stuff, Willy Wettstein, Rimpl and Le Roseau Chantant. Steel is understandably proved to be much longer-lasting than brass.
You will note that the following list contains a few minor discrepancies between sellers, along with more serious errors, for several of the American template widths, along with a few others, must already have been converted and intermingled. The original list is that supplied by Herrn Hörtnagl. Items of doubt, or of undoubted error, have been marked for correction in Orange or Red.
So the help and amendments of readers would be much appreciated, if you would please contact me to offer True metal widths that have been carefully measured in person (if only at the template centre). The oboe fraternity will thank you likewise.
Although these conversions have been created in good faith, I can sadly take no responsibility for errors that lead to purchase. You are welcome to copy the tables for your own use, but not to publish them, please. They remain Copyright © GS 2020.
Templates for the English Horn, Oboe d'Amore, Musette, Bass/Baritone Oboe, Wiener/Viennese Oboe, and Baroque and Classical Oboes may be found from these links, along with the measurements of Shaper-Tips for comparison: Oboe, Oboe d'Amore, English Horn, and Baroque & Classical Oboes.