I've been using this method ever since I discovered Sew Inspired's tutorial.
I'm just not a fan of envelope closures; they look kind of sloppy and don't keep a good form, but many people assume that it's the easiest option. However, this method is almost as easy and gives much better results!
I love adding a machine stitched binding for the final touch. :)
If you want to make a simple pillow out of decorator fabric, this method works well also; just sew your pillow right sides together and skip the binding part.
OK, here goes!
First, prep your pillow top and square it up. If I have machine quilted the top, I like to seal the edges of the machine quilting by stitching 1/8" from the edges.
Cut the backing fabric about 1/2" wider and 3-1/2" higher than your prepped pillow top. This will allow for shrinkage when fusing the interfacing.
If I'm using quilting cotton for the backing fabric, I like to interface it with Pellon fusible Shape Flex 101. It gives quilting cotton the heft and feel of decorator weight fabric. It's a little pricey, but I usually buy it by the bolt from JoAnn's when I have a 60% off coupon.
Cut the interfacing slightly smaller than your backing fabric and fuse according to manufacturer's instructions. A damp press cloth is helpful. Be sure to fuse for the full amount of time recommended by the manufacturer!
Now, slice 6-1/2" off the narrower edge. (This will be the top of your pillow back.)
Choose a zipper that is long enough so that the zipper pull and metal stop extend past the sides. This way you won't have to worry about your needle hitting any metal parts, resulting in breaking a needle or messing up the timing on your machine. And, the zipper pull will be off to the side and won't require you to slide it out of the way.
Center the zipper right side down on the narrower top piece of the pillow back with the zipper tab to your left; line up the edge of the zipper tape with the edge of the fabric and clip in place with Clover Wonder Clips.
This is what the Bernina zipper foot #4 looks like.