It’s not recommended that you use a “permanent’ keyboard cover for protection, but squeezing a pricey, portable Mac into a backpack and leaves key-ish smudges on the screen. My favorite solution to the problem is the US$15.94 Laptop Swiper
It’s a laptop screen protector, keyboard cover, and microfiber cleaning wipe all rolled into one. Made from SumiTex, it lays over the keyboard and cushions the entire screen when the laptop is closed. When the laptop is open, just remove it.
Available in a variety of sizes, the Laptop Swiper works with 13-inch, 14-inch, 15-inch and 16-inch MacBook Pros and MacBook Airs.
So why not use a keyboard that you place on the keyboard and leave for long periods of time. As noted by Lifehacker, there are a couple of drawbacks:
° Keyboard covers, while thin, aren’t that thin. They end up touching the display when you close your MacBook, and it stays that way until you open the computer back up. Immediately, you’ll notice that there is a QWERTY imprint on your MacBook’s display, which fits in nicely with whatever other gunk has accumulated here.
° Keyboard covers can keep your Mac laptop running too hot.
