After discovering my first glass nail file, I've been hooked. Unlike emery boards, glass nail files never go dull; they need only a quick rinse under the tap to be good as new. My Sephora file is a grid of teeny, tiny upraised rough glass nodules. Think frosted glass, but maybe a tad rougher. The file is thin, but sturdy enough for me to feel confident that it won't break when my klutzy self inevitably drops it on the floor.
You use it just like any other nail file, but it feels significantly less abrasive. There is no pulling or snagging on the nail tip, which prevents cracking, peeling, and splitting of the nails. In fact, it is so gentle that you can use it safely on acrylics or on damaged or fragile nails. The only drawback? Using it reminds some people of nails on the chalkboard. But if you're interested in checking out a glass file, it's a relatively inexpensive investment. A company called 95° and Sunny makes hand-painted ones — or you can always start out with my $8 special from Sephora.