So recently I've been led to the conclusion that there aren't really mask-like clothes in the game. While there are full-facial helmets, that isn't quite what I'm thinking of. Here's a brief outline:
The masks I imagine would in most situations be made of a hard plastic or fiberglass-like material. They would hide the face, like a helmet, and depending on the material would offer a small amount of facial protection (at least to bladed weapons) but would not cover the whole of the head, so you could still wear it with say a hat or something.
The main purpose for these would essentially just be for fashion. Security organisations looking to intimidate, serial killers looking to hide their faces, rich corpies having a cyberpunk-error masquerade, festivals, the list of potential and trivial uses goes on.
Also ballistic masks. That shit's intimidating and gives more serious facial protection. They'd also be able to be worn with helmets that aren't full-facial.
You know you want to see someone walking down the street in a construction helmet and a deathmask. Don't lie.
Anyways, anyone's thoughts and other suggestions are welcome, and GM's should totally do their scripting magic to make these possible.