The mysterious case of the mattifying topcoat

...I don't mean an intentional mattifying topcoat, like Matte Magic or Matte About You. I mean a normal, everyday, glossy topcoat, that starts turning things matte.

This is my friend, Sally Hansen Maximum Growth Quickdry Topcoat. As you can see, the label boasts "dries color in 30 seconds". Well, maybe not quite that fast, but it's a quick-dry topcoat that dries hard and glossy, without tipwear, and it has served me well. Until now.

Look what happened to a recent manicure.

See my index finger, on the right? There's a large, matte spot that appeared on the nail as the topcoat dried. What is causing this? I don't know. But it's happened several times.

It began suddenly, and it's fixed by simply putting another layer of TC on, but it's really puzzling. Practically every manicure I've done with this topcoat has resulted in one or two unsightly matte or satin spots.

I asked around on Makeup Alley and it has happened to some other people too, but no one knows why. I used this bottle of TC for several weeks before this started happening. It was probably old when I got it, but it was still sealed til I opened it myself. It's so mysterious...

Nailgirl