I aked this elsewhere, but the canon program seems to make the chin strap too narrow. I generated a female Harris hood by hand using the version of the canon published in an older version of NAFAHH (4th printing--1976). When I input the key measure of 2" (or 50 mm--close to the 47 given for a Texas female), the printout from the program matches up pretty will with my hand-drawn version except for at the seams over the eyes and the chin strap. The front portion of the seams in my hand-drawn version are much more rounded, and my hand drawn chin strap is noticably wider. Any ideas why this might be the case?
Pete, It is a simple computer program that draws a pattern you would cut out of leather to make a hood. You have to correctly measure the brads head for the fit. The numbers for the chart are if you do not have a bird to measure, but want to make a hood that may fit. You can do a search for the program it is out there, but I do not know if you have to run it in 32bit rather than 64, but I would guess so. If you have an old XP machine try it on that first. In my opinion buying your first hood is cheaper than making one yourself, due to buying leather, tools etc. plus, you miss all the fun of sewing for hours before realizing you did it wrong...
If you want, you can try the hood generator program I wrote. Click to download it This program will only run on Windows based machines. In addition to the Slijper's Canon pattern, it also has a few others. The pattern the most people seem to be using from my program is the Gerrish Three-Four-Five Canon pattern.