This mod allows you to wear cosmetic masks. Due to limitations with modding UMA, the usage for these masks is a bit different than just “wearing” it in lieu of clothing.
There are two types of masks; Items, and Item Mods, that you would place in a head cloth/armor slot.
Guppycur has added blank masks to the loot tables for the sporting good groups, which will allow you to make the mask items that are wearable. If you want to make that item into an item mod, simply convert the item by clicking on recipe to create the item mod; no additional materials necessary. Currently, you cannot revert the change.
For the item, you would hold the mask from your toolbelt as an item and left click to apply the cosmetic change. The mask remains in your inventory so that you can right click to remove. You must hold the item in your hand in order to apply and remove the mask.
Known exploit: You can apply the change, then drop the mask for another to use. You wouldn’t be able to remove the mask unless you have the item back to right click.
Known bug: If you have access to DM, you can F5 and P to view your character in 3rd person view, however returning to 1st person view will show the interior of the mask over your face, obstructing your view. This is actually a vanilla bug (reported) that affects the leather knuckles as well. The fix is simply, if you used the item, to right click the item. If you are using the item mod, simply remove/reset the head gear the mod is in to fix the visual obstruction.
Here’s a video demo of how to use it and the bugs that you will find when using it. Since the time of the video he has fixed the recipes, the typo, and renamed solvent to White Dye.
Updated so that only one mask at a time can be worn.
The forum topic of the mod is here.