Ladies and gentlemen, welcome back!

After making my first Instructable, it took up until now to make the sequel. Don't ask me why, this is how these things go, now and then. Life, she's a wily one ;-)

That first Instructable is actually the preparation for what I consider the 'main course'; making a full face mask. The sole reason for that head mannequin's existence is the mask I've made, and is used as an example here. I'm not much of a sculptor, so I'll be 'cheating' by (partially) using store bought prosthetics.

Let's get going!

Step 1: Preparation - Materials & Tools

Before starting on making your full face mask, you need to gather a few materials:

A hood/coif that covers most of your head. The cotton kind worn by motorcyclists under their helmet is ideal. Depending on the exact design of your mask, you need to look at how much of your face needs to be covered by it.
Existing prosthetics and/or masks. Depending on how good you are at sculpting, you can 'cheat' by incorporating existing prosthetics and masks into your own mask. Make sure they're latex, rubber or an other kind of flexible material!
Latex or liquid rubber. This is used in combination with materials number 4 and 6 to create the 'generic' skin of the mask.
Paper towels and cotton swabs.This is used in combination with material number 3.
Glue. Any kind of glue that'll be able to affix existing prosthetics and/or masks to the hood/coif. Make sure that it's a kind that's still flexible when it's dry.
Water-based, non-metallic paint. This is used in the final stages to give the mask it's final appearance.

Tools used:

Scissors. To make changes to the existing prosthetics and/or masks, if you use those.
Craft knife. See above.
Sculpting tools. Only if you need them to sculpt your own details, obviously. I didn't need these.
Paint brushes. The inclusion of this item hopefully speaks for itself ;-)
Your head mannequin!

Step 2: Affix Existing Prosthetics And/or Mask(s)

If, like me, you don't feel confident enough to sculpt the entire mask yourself, you can 'cheat' by glueing store-bought, aesthetically pleasing prosthetic(s) and/or mask(s) to the cotton coif. Given you've chosen the right kind of glue, it should be a matter of following the glue's instructions and waiting.

Here you can see that the bulk of the detail for my mask came from a large, rubber half-mask and latex Demon horns. In a later stage, I removed the ears from the half-mask and placed them in a more realistic place on the mask.

If you don't use existing items for the details of your mask, you can, of course, move on to the next step.

Step 3: Blending and Skinning

The next step is two-fold.

First, you need to blend any mask and/or prosthetics you've glued to the coif into each other. Use the cotton swabs 'drenched' in either the latex or the liquid rubber as the 'meat' and keep fudging until it looks a coherent, smooth whole.

Secondly, especially on the parts of the mask where there are no prosthetics or existing mask, you'll need paper towels drenched in either the latex or the liquid rubber as skin. Obviously, if present, it needs to blend into existing details. I recommend at least four layers of 'skin'.

Between layers of cotton swab and paper towel, you can let it dry. Both latex and rubber stick well to themselves and although I mostly worked while they were still wet, you should be able to work with dry layers. Luckily so - in my case, this step took place across several evenings.

Both cotton swabs and paper towels drenched in latex or liquid rubber are quite malleable. If you have more sculpting talent than I, this'd be the step where you sculpt details into your mask.

This is also the step where the head mannequin comes into play; the mask in progress is placed on it. As said, this step can take multiple days. Being stored on the head will prevent undue warping while the masks gains in layers and thus in strength. If you do this step with the mask resting on a 'generic' mold, it's entirely possible the end result will be too big or too small for your head.

Step 4: Painting

The final step is painting the mask. Depending on what kind of mask you want and what kind of detail you want, you'll have to break out several kinds of brushes. Here, I used two; a big one for the skin, warpaint and eye sockets, and a small one for the fine detailing on the horns.

Most paints are rigid when they're fully dry. This means that on a flexible mask like this, it'll crack in no time, leaving your full face mask an ugly mess. Therefore, you should mix your paint with your latex or rubber and use that mix as the final layers of skin, giving your mask it's final colour and appearance.

However, as said, you'll want water-based, non-metallic paint. The metal particles in metallic paint 'corrode' latex and rubber, leading to a bad looking end result.

That's 'all' there is to it! I hope you enjoyed this Instructable.