When I sew the binding strips together, I don’t like to sew this straight seam. I like to sew a seam on the diagonal to help avoid bulk. I’ve put two samples together here to show you how this works.
On this piece of fabric, I’ve sewn this straight seam. I’ve pressed toward the dark. Here’s my seam. Notice what happens. I have one, two, three thicknesses of fabric here and when I fold it, there are three more there. So that’s a total of six pieces of fabric. When I take this over to my quilt edge, I’m going to fold this over and what’s going to happen now is: I have six layers of fabric plus another six layers. And you get a bump in your binding and you want to avoid that.
When you sew on the diagonal like this and you press open those seams, this part of the seam goes in this direction and the other part of the seam goes in that direction. And so you don’t have all those layers on top of each other. not on top of each other. When you bring this over to your quilt top, and your fold it over – you can see here you still don’t have those seams lining up on top of each other. And the same happens on this side. You see the seam misses the other seam. So when you sew a diagonal seam, those seams are going to be evenly distributed so you do not get a bump on your binding.