I can go on and on, but you did ask.... :-)
As stated previously, the best bindings are:
1. Sewn on the front and hand stitched on the back.
2. Stitch the mitered corners closed BOTH front and back.
3. Make sure the “batting fills the binding”...this means when you pinch along the edge of the binding you should feel batting all the way along the edge with no empty areas. You should not feel just the binding fabric.
Other things the judge looks at:
4. Binding should be the same width along the entire edge.
5. No “dog ears” at the corners.
These are the main things, but this is the important part.......
It does not matter HOW you apply the binding AS LONG AS IT IS DONE WELL. That is the most important thing to strive for!!! If you can apply with a sewing machine on both sides and you DO IT WELL that is fine.
This also means, even if you are hand sewing, you must do it well. Bindings that are not well done can make or break getting that ribbon!
Good Luck at the Fair!!!
PS I judge the County and State Fairs in Colorado and Wyoming.