I'm just gonna start by saying this is my third try at making this stupid mask and that there's gonna be a lot of this is what I did, but you should do this instead in this tutorial. The mask ended up costing around forty dollars to make most of the money going towards the Gesso and the Polymer clay which could both probably be substituted with cheaper materials if needed.

Step 1: Gather Your Materials

What you'll need:

Hot glue gun and hot glue (alot), Scissors, Ruler, Gesso, Paint (black, red, white), Paintbrush Craft foam, Black fabric of your choice (Vinyl Pleather is used in this tutorial), Polymer clay, Two to Three zippers, Sew in snaps, Thread, Sewing machine, and plenty of refs.

Step 2: Make Your Pattern

Method 1: This is the method that I used although I don't recommend it as method two seems much easier. Essentially what you will do is take measurements of your entire face and neck and then continuously fit it to your face until you get it to fit right.

The measurements I took were:

Ear to jaw, jaw to chin, over my mouth from my jaw, over my nose from under my ears (picture 1 of the first picture), and bridge of my nose to chin (4th picture on the first picture). For the neck they were chin to collarbone (3rd picture on the first picture) and the area around (2nd picture on the first one).

I would then hold it up to my face/neck and trim it/add paper until it fit then transferred it over to Craft foam and did the same thing since it had a stiffness closer to that of the fabric I chose to get the closest fit I could. I redrafted the neck many times until the curve was right. The mouth was mostly guess work as well (I would recommend practicing drawing the shape a few times until you're satisfied with how it looks).

Once I was happy with the pattern I transferred the final draft back onto paper and added a 3/8 inch seam allowance to all edges.

The eye patch is much easier to do. You pretty much just cut out a rectangle that can cover your eye and add two straps to the sides. I sloped the sides so that they would avoid my ear and other eye.

Method 2: This is my preferred method of drafting patterns, but I didn't have any painters tape at the time. What you would do is wrap your face and neck in cling wrap over any part the mask would cover (leaving holes so you can still breath) and cover that in painters tape. Get a friend to help if you can. Then you would cut yourself out and draw out the seams so that you can recreate it out of fabric. You would then transfer it over to paper and use that for the next few steps. If that doesn't make much sense then here's a video from Kamui cosplay explaining the method better:

Step 3: Transfer Pattern Over to Fabric

Next thing you're going to need to do is take your paper pattern and transfer it over to the fabric you chose. If you decided on a fabric that's edges fray you'll need to fray check the edges and take other precautions since the seam allowance is smaller than usual. Make sure to keep a seam allowance inside the mouth as well. I recommend that you mark up the wrong side of the fabric to be sure that it retains the shape it should when you sew it down.

Step 4: Sew Together

Pretty self explanatory, pin together all your seams and run them through a sewing machine. It's probably better if you don't use pins on any sort of vinyl unless you can hide the marks it'll leave. Be careful around the nose, you might want to hand sew that part rather than put it through your sewing machine. I also ended up top stitching all of the seams down since I was unable to iron down my fabric. Don't forget to sew a zipper into the front seam on your neck.

If your zippers end up being too long like mine did and just cut off the top and fray check the ends with hot glue which doubles as a stopper for the zipper. In order to close the mask in the back around my neck I used a separating zipper, but I feel like snaps or clips would be much more forgiving instead if your pattern doesn't fit perfectly.

Step 5: The Teeth

The teeth were made out of polymer clay. You just need to start out by rolling the clay into small balls and then forming them into variously shaped teeth. I used my own teeth as reference for this and made just enough to fill the hole on the mask. I found that the flatter I made them the less they interfered with the zipper later. Anchors made out of cone shaped bits of clay were molded on the backs in order to stop the teeth from falling out like last time during the convention (picture 1). After baking the teeth in the oven I drew out the shape of the mouth on more craft foam (scrap fabric works better in this situation since it makes the end product more flexible) and added a large amount of seam allowance when I cut it out. I then lightly tacked the teeth onto the craft foam with hot glue.

Step 6: The Gums

Next you'll need to take the rows of teeth you've made and start mounding up hot glue over the anchors to cover them. Avoid the body of the teeth as best you can and build up ridged to simulate gums. Use the tip of your hot glue gun to smooth out the gums a bit and spread the hot glued around until you're sure there's no craft foam showing. Once you're happy with the shape let the hot glue dry and paint at lest three layers of gesso over the whole thing gums and teeth. Once that's dried get some black paint and work it into all of the cracks as best you can in order to give the illusion of depth and grunge. Wait for that to dry and paint the gums red while trying to leave some of the indents black. Next clean up the teeth with more gesso and if you want add a coat of white paint over them. Seal the entire thing with a flexible matte sealer. Now that the painting's over with go ahead and glue your zipper between the teeth and then the teeth into the mask.

Step 7: The Final Touches

We're going to go back the the eye patch and cut out an "x" for it out of craft foam. Round the edges and cover it in the same fabric as your mask. Hot glue down the edges; cut out darts and trim edges as you go. Once it's good poke holes and stick studs in through the front all the way through the patch attaching it together. Do this to all four corners. You can also stick one of the studs into the edges of the nose and attach thread to it to hook over your nose. Then sew snaps onto the ends of your eye patch and over where the patch attaches to the mask to connect them together. Finally the screws (which I forgot to take pictures of) in the sides of the neck can easily be drafted out of Craft foam, gessoed and then painted silver, sealed, and glued onto the sides of the neck right under the jaw.