So this year for Halloween my family decided to remake an old family dress-up photo, and I was to be a skeleton. Not keen on wearing a tacky store bought skeleton mask I decided to make my own. I didn't think I could do a full skull in 2 weeks, so I compromised and made a half-skull mask and filled in the rest with make-up. Decided to use Monster Makers Clay as the base and cast a mold using EastCast polyurethane resin, opening up the option if I want to reproduce/sell it to others.

Materials:

Sculpting Medium and Tools- I used Monster Makers Clay, super nice to use, little expensive though. As long as any sulphur-free clay is used to avoid messing up the molding process.

Plaster Cloth and Latex-Free Gloves - Needed for the mother mold and to keep mess to a minimum

Molding Silicone - I used Pinkysil (local product, equivalent is the Smooth-On)

Casting Resin - I used something called EasyCast, very light weight and cures white at Shore 73 hardness

Paint and straps - Using acrylics and some elastic straps lying around the house.

Step 1: Sculpting Your Skull

Total forgot to take a photo of the final sculpt, oh well. I took a cast of my face using gladwrap and the plaster cloth so the end mask would fit my face properly. After softening the clay in the microwave (3-4 min for a full 5 pound tub), I took small strips and put them into the basic shape of the half skull, leaving holes for the eyes and nose. It's best to build up various parts such as the ridges and either shape it with your fingers when it's warm or shave off the clay using the loop tools until it looks satisfactory.
Once majority of the shape had formed smaller details can be carved into the mask, such as cracks in the skull, holes and teeth (if you're good enough to sculpt them). I could get a decent shape for teeth with the clay, so I did a quick cast of mine by biting into the clay and pouring in a small amount of EasyCast. This got attached to the skull and final details and smoothing was done.

Pro-tip for smoothing, paint Artist Turpentine or Cleaning Alcohol (fairly high, maybe 90%) over the clay to smoothen out any small imperfections or 'scars'. It dissolves the clay and you can use a paper towel or loop tool to easily remove anything left.

Step 2: Molding and Casting Into Plastic

Now to make it wearable. The Pinkysil silicone is a two part mix with a 1:1 ratio for volume, so pour them into 2 equal containers (part A is white, part B is a darker pink) and mix it until it turns light pink (around 20-30 seconds). This cures fairly fast so pour it slowly onto the sculpt, making sure to pour from a high height to reduce any bubbles trapped in it. I also built a small wall around the base of the mask to reduce the waste and give the edge of the mold skin a thick base (which helps when casting) in most cases. I did batches of the Pinkysil in smaller amounts (around 100ml per mix) and kept doing that until I felt the skin was thick enough to take off. While this brand is fairly strong and tear resistant, other brands like Smooth-On may need a thickening agent to bulk up the silicone (too expensive to get in Australia).

Once the mold has cured and is safe to touch you can build a mother mold around it out of plaster wrap, which is to keep the masks shape when casting it. Just layer on a decently thick amount of plaster and wait for it to dry. Once it's done you can remove the mother mold and carefully remove the silicone, just loosen the edges and peel it right off nice and slow. Now we can cast it in resin.

EasyCast is really easy to use, just mix it up in a 1:1 ratio and stir for 15 second or so (you should see the different coloured parts blend properly), and pour it into the silicone mold. These products are good because they are self releasing, so you don't need to spray any down on the inside of the silicone (may be needed with other products, research before you ruin an expensive mold!). Once poured in just keep rotating and swishing it around, getting into all the cracks and along the edges of the mask. Once it cures, keep doing thin coats until you think everything looks strong enough in certain parts, I did 3-4 coats and made sure the raised ridges were all good before finishing.

Leave it for a couple of hours and you can remove the plastic cast, being careful not to rip the silicone mild. As you can see mine came out beautifully, very clean and exactly what I wanted (had to dremel out the nose and clean up the edges though). Give a light sanding if it needs it, maybe 320 grit or higher, and now we can make it gritty.

Step 3: Make It Dirty, and We're Done!

I needed this for a Halloween party and I wanted it to look gritty and dark, so I did something called black-washing. I took some black acrylic paint and watered it down at about 1:1, and started painting. Now to blackwash you need to paint on a weakened colour and wipe it off fairly quickly. Yeah wipe it off. Get the paint into the cracks and crevices of your mask, paint the rest of the area as well, and using a paper towel give it a good wipe. This should leave paint in these hard to paint places and smaller detailed areas, and give the whole area a washed out colour (I used black, but you can use anything). It's best to do sections of the mask at a time, and paint in thin layers to slowly build up the colour over time to give paint depth. Eventually you'll finish and get something like above, darker paint lines in cracks and an overall colour to the mask. Finally you need to attach some straps to keep it on your face, I just super glued some cheap elastic on the sides and that works fine for me.

And there you have it, a decent quality skull mask for your spooking needs. Most of these techniques can be used for most projects, it just a manner of having the time and *cough* money *cough* to do stuff like this. Overall this took me around 3-4 hours sculpting and a 8 hours doing the molding, casting and painting, so it can be knocked out in a day or 2 if you wanted. Happy Halloween.