I bought an Apple M1-powered MacBook Air laptop and bought a laptop cover to protect it against scratches and mild impacts. The hinge mechanism of this machine presents a challenge for case makers: there's not much clearance to work with. Letting the lid open past 90 degrees is a tradeoff between protection and adding stress to the laptop joint. The first case I tried(*) had a very noticeable "bump" that my lid had to push past, and I worried about long term durability of the hinge under that stress. I then tried a different vendor (*), whose back corner (where the hinge is) is thinner and potentially more fragile but it put far less stress on the laptop hinge joint. Even though I could feel a bit of a bump as I open the lid, I decided to stay with this case which has worked very well over the past three months.

The same could not be said of the keyboard protector membrane that came bundled with the case. Historically I had not used such things and its inclusion did not factor in my case purchase decision. But since I got it anyway, I thought I would give it a try.

The good news: it is very good at its primary purpose of protecting the keyboard from small particles, like food crumbs that get dropped when I use the laptop while eating.

The neutral news: I had been worried about how it would change the keyboard feel. I'm a touch typist and particular about how my keyboard feel as I type. (I never got a "butterfly keyboard" MacBook for this reason.) And while the keyboard tactility definitely feels different, I did not find it objectionable. At least, at first.

Now we come to the bad news, part one. After a few months, the membrane material starts exuding some kind of liquid. There doesn't seem to be any odor and there's very little of it, but it starts leaving blackened blotches where the liquid touches the keyboard and made the membrane more transparent than other areas. This looks bad and I worry about getting that stuff on my fingers. The membrane never gets tacky enough to stick to my fingers, but it still doesn't feel good to the touch.

The bad news, part two, is in the flexible nature of the material. After using it for several months, the material has started to stretch. If I try to keep the shape aligned with the keyboard, the stretched portions would bulge up which looks bad. Plus when the laptop lid is closed, these bulges touch the screen and leave behind little spots of the aforementioned liquid.

If I smooth out the bulge so the membrane lies flat, its shape no longer align with the keys. This is especially obvious in the arrow keys in the corner, where the designated bumps for arrow keys are now 2-3mm further to the right than the actual keys themselves.

Due to this unsightly shape, black spots, and sticky sensation, I'm going to throw away this membrane. It was a low-cost test so no big loss. But if I ever get serious about putting protectors on my keyboard I know to either (1) look for higher quality material or (2) budget for frequent replacement.