QuiltE

QuiltWoman ... just checked my notes and I use ...
1-3/4" for the flange part (wider now, but becomes the narrow flange)
and 1-1/2" for what will become the wider part showing on the front of the quilt

You can adjust your widths, depending on how much of each you want to have show once done.

Agree, best to test before doing all your cutting and stitching. I usually make a pot holder, mug rug or vase mat for my test run.

Peckish

My math is very easy - the flange fabric simply needs to be 1/4" wider than the binding fabric. This will give you a 1/8" wide finished flange, no matter how wide or narrow your binding is. Of course, if you want a wider flange, than make it 1/2" wider than the binding fabric, and so forth.

mkc

Here's a 4th version - Charismah's uses 1 5/8" for flange color and 1 3/8" for main binding color. That's what I do.

sloscotty

I made my flange color 3/8" wider giving me a 3/16" finished flange.

Quiltwoman44

Oh that looks very nice indeed. I may have to do another one!