Join Date: Nov 2011
Location: Beautiful Pacific Northwest
• Horses: 0
Get a flexicurve. You can get them online, or at craft stores, or at fabric stores. Quilters use them to cut cool patterns in fabric. If that's not an option, straighten out a coat-hanger wire.
Find the rear edge of your horse's shoulder-blade. Go 2" further back, then lay your flexi-curve (or wire) over the withers/back and get a good tracing or mould of your horse's back shape. This location is important, because it's pretty close to where your saddle's tree points will sit. Now lay your tracing down on a piece of cardboard and trace it. If you cut it out, you can take your "horse" saddle-shopping and make sure the angle of the tree on the saddle you buy matches your horse. Or you can take a picture and send it to online shops, and the good ones can help you find a fitting saddle.
Do the same thing along the length of the back. Start at the withers or about 2" behind the shoulder-blade. Do your tracing about 1-2" to the side of the spine - where the panels will sit. You can take that shopping with you or send it to a seller as well.
Note that on English saddles, what one maker calls a medium may be very different from what another calls a medium. They all fit differently. In general, an angle between tree-points of about 90° is a medium. Wider is M/W or Wide, narrower is the narrow sizes. But all the makers have different shapes to the tree - some U-shaped, some V-shaped. Some have narrow gullets, some wide ones. Your tracings are your friends. There is no standard. Or to put it bluntly, it's a bit of a crap-shoot.
At least when you get your tracing and see the angle, you'll have an idea of whether you're looking for medium, wider, or narrower trees.
When you get a saddle, you'll be looking for the tree angle and shape matching your horse's shape. You'll also be looking for the panels making full contact with your horse's back. There's a sticky on here called "Does you saddle REALLY fit" which has the 9 fitting videos from Schleese. They're worth a look once you put a saddle on your horse.