What Is The Flap On A Pillowcase For?

Pillowcases are simple, but the more you look at them, the stranger they can be. They're just open pockets of fabric to hold your pillow, but there are some interesting variations in how they're made. If you want to reuse your old pillowcases, it might be helpful to understand the anatomy of a pillowcase. Some keep your pillow in place with a zipper, others are just normal sacks, and some have an extra flap of fabric. That extra flap may seem designed to catch other items in the washer, but it's actually meant to keep your pillow from sliding around inside the pillowcase!

The extra flap of fabric is called an envelope closure, and it works just like a paper envelope does. Once your pillow is inside the pillowcase, you can pull the flap up and over, tucking the pillow safely into place. There are a few benefits to using an envelope closure style over other types of pillowcases. Since the envelope flaps are made from fabric, they can keep the pillow in check without causing any major discomfort. 

Pillowcases with nothing securing the pillow may be comfortable as well, but your pillow might shift throughout the night. Readjusting it anytime it moves too much is a minor annoyance, but it's also something that can be avoided relatively easily. Zippers and buttons are more effective at keeping your pillow inside the pillowcase, but if you're a restless sleeper, you may find yourself rolling onto them, making for an uncomfortable night's sleep. Not to mention, they can break over time, and people with certain disabilities may struggle to fasten them. Additionally, since the flap hides the pillow completely and is typically made from the same fabric as the rest of the pillowcase, it can create a more cohesive and elegant look.

While the flaps have plenty of benefits, there are a few reasons you might want to pick a different style instead. Since envelope flaps don't attach to anything when they're folded over the pillow, they can still shift and potentially unfold if you're particularly restless or your pillowcase is the wrong size. Make sure you know the difference between standard and queen pillow dimensions and order the correct size pillowcase, as one with an envelope closure that doesn't fit right won't be as secure. If you're a restless sleeper, even a properly fitting pillowcase may shift over time. While you'll hopefully only need to adjust it occasionally, it can still be annoying, so you should keep that in mind.

At their best, envelope-style pillowcases look more elegant and streamlined, but they can also appear a little odd or asymmetrical at times. You may end up with extra wrinkling if the flap isn't fully smoothed down, for example. Since the flap is an extra layer of fabric, it can create a slightly asymmetrical look as one side of the pillowcase is thicker than the other. This may not be very noticeable, but if you're particular about the way your pillowcase looks or feels, then it could become a nuisance. In that case, you may want to switch to an open pillowcase or one that uses a zipper or buttons. 

If you like the look of an envelope closure pillowcase but don't like the feeling of sleeping on one, there is another option. You can use this pillowcase hack from Nate Berkus to fold a bag pillowcase, making it look similar to an envelope closure during the day. At night, just untuck the end for one smooth layer of fabric.