I started this project off much like I had Tobi's mask - with Crayola Model Magic.
Unfortunately, I rapidly discovered two things about this mask. One is that this was going to need to be much thinner than I first expected, and second was that the eyes of the mask, in a screen shot of the anime, are further apart than actual human eyes. I needed to remedy both of these problems.
So my first step was to work out a new design for the mask. I began by making a basic shape on paper of what I thought the mask looked like. In some images of the mask, the chin is more rounded and in others, it is quite pointy. The rounded but slightly pointy chin was a mix of the two. I also discovered a new material to work with at this point while searching for a material that would be a cheaper substitute than wonderflex. It is called Sintra, which is used in sign making, and is heat moldable. Unlike wonderflex, it is smooth on both sides, comes in many different thicknesses, but does not stick to itself. It is also quite cheap (a 4'x8' sheet was 40 dollars from a local place) so I was pleased to give it a shot.
Here you can see three variants on the mask in one shot. The farthest right is the paper mask I worked out with eyeholes. The one on the far left is the previous attempt with model magic, and the one in the middle is my first experiment with the Sintra. I discovered that using a heat gun, as I did with wonderflex in the past, worked but it could 1) burn the Sintra leaving scorch marks and 2) did not heat it evenly enough to get a smooth flow.
This was my first real attempt of the mask. I discovered that by putting the Sintra in the oven at 200 degrees, it turned as flexible as paper. I only had to gently hold it in the position I want for about a minute in my hands, and it stayed perfectly in that shape. I also quickly drilled the eyeholes so I could start to see what I was doing.
It was about this point, as I sketched on the eyes, that I realized I needed the mask to be flat to cut out the eyeholes instead of curved. I also realized the mask was too long and would not fit properly under a wig. So I made a second mask and this first mask became a 'test mask' so to speak.
The eye holes were 'hidden' in the screen shots, so I improvised. From a left over pair of pantyhose from my Deadmau5 head, I used a sharpie to color them black and hot glued pieces of it stretched over the eyeholes. The pantyhose all but melted into the hot glue, which I quickly realized was a requirement to keep the hose from running. The illusion worked very well in a quick test with a camera and flash. I could see well enough through the eyeholes to not be concerned and they could not see my eyes.
I used black paint around the edges of the eyes to help further the illusion of the hidden eyes, and covered the mask in white gesso. The Sintra is easily damaged by nearly anything, and this hid any marks from sanding. It looks perfect in pictures, so I was pleased.
I cut templates for the lightning bolt over the eye as well as the mouth. Again, some compromise had to be made with the mouth. In some images it is 'smiling' and in some it is 'flat'. We went with this. The over all mask highly pleases me. The simple solution of the eyeholes turned out to be a very positive one, and the material choice has led me to believe I will be making all further masks with Sintra. I still have mounds of it left over, eep!