You've heard of silk pillowcases to keep your hair smooth overnight, but what they can't quite help with is keeping your straight hair straight and your curls intact. That's why hair bonnets are a must overnight. They are often lined with satin or silk to ensure that when you wake up your hair will look exactly like you left it (via The Strategist).

If you're looking for a silky inside to keep your hair smooth, Byrdie recommends going for Silke's London Hair Wrap. The bonnet comes in a cocoon shape with a knot front that helps secure it all night long. Sometimes you'd like to protect your hair 24/7, especially if you're working with a temperamental weave, so it's important to find one that's going to look as good as it's treating your hair. For a hair bonnet that you're comfortable being seen in, you should opt for one of the many pretty luxury patterns provided by Yeli Yeli Bonnet (via Elle). The range comes in some unique, stunning Ankara prints.

Lastly, a popular reason to use hair bonnets for super curly hair types is to keep the curls bouncy. Nothing is worse than using all the right gels and mousses to get those perfect ringlet curls, only to sleep and wake up to find a frizzy wavy mess. For curls, Glamour recommends Only Curls Satin Sleep Turban that retails for only $21.