A lot of prosthetics are sculpted on top of a generic head. You can buy these heads at a few different online stores, but no prosthetic you sculpt and mold off of those are going to fit perfectly on your model. At these points, you're going to want to make a mold of your actor/model's head and sculpt directly on top of that.
In this instructable, I'll show you how to make a mold of a head in a fairly cheap and easy way. I do suggest if you've never done this before to first do a simple face mold first!
- Plaster Bandages
- Ultracal (you can use plaster of paris but I would highly advise against that)
- Alginate (1.5 pounds)
- Plastic Bags
- Bald Cap
- Permanent marker
- Pros Aide and Pros Aide remover
- 5 gallon buckets
- 1 gallon bucket
Step 1: Step 1: Cover Your Model's Head!
First things first, have your model take off their shirt and cover them from collarbone down with plastic wrap. Alginate does not stick to hair, but it will rip very easily. Keep alginate away from clothing.
A bald cap is ideal in this situation, but if you are unfamiliar with bald cap application or are short on funds, saran wrap will do. Tape around the edges of the forehead and neck. If you model has long hair, gel the hair down so that it lies flat along the skull.
Step 2: Step 2: Plaster Gauze
Break out your plaster gauze and start covering the back of the skull. Many people will continue to use alginate around the back of the head, but if you don't have the materials plaster gauze will work fine. It will, however, cause more sanding at the end.
Cover the back of the model's head just to the center of the skull and back of the neck, avoid undercuts around the throat and top of the head. If it couldn't pull straight off, you've got an undercut.
Step 3: Step 3: Alginate
Mix your alginate with cold water following directions on the packet. Warm water will make alginate set at a much faster rate. This alginate will be applied with your hands to the parts of your models face that is not covered with gauze.
Don't overlap the gauze, the alginate will stick to it and potentially rip. I generally start with the nose, that way the alginate will harden around their nose first. This makes it easier to be sure your model can breathe. I don't put straws in my model's nose because it distorts the nostrils. Just watch their nose and make certain they are able to breathe.
Let the alginate sit for 10 minutes or until completely hardened.
Step 4: Step 4: More Plaster Gauze
Cover the edge of the back head plaster piece with vaseline, about 1-2 inches from the edge. After this, start covering the alginate with more plaster gauze. You're going to overlap the plaster gauze over the back piece. Work the gauze as close to the alginate as possible and avoid air pockets. Those will cause lumps in the final head casting. It is also acceptable to mess with your model at this point. Smiley faces are always fun!
Let the plaster set for at least 10-15 minutes. It should be cool to the touch and hard.
Step 5: Step 5: Pull Off the Piece!
When they pull this off, have them lean forward and cup the plaster in their hands. You'll have to help the alginate let go of their head, because it has a pretty good suction on it. Run your fingers along the insides of the alginate and let it naturally let go of their face.
Step 6: Step 6: Seam, Pour, and Break It Out!
At this point, seal the two pieces together with more plaster gauze around the edge, at least 4 layers. This will give you one solid piece to pour your ultracal into.
Putting the head into a bucket so that there's no need to hold it. Mix up your ultracal or plaster following directions. I suggest ultracal or a gypsum for a head to sculpt upon because the material is naturally harder. Plaster will start breaking apart somewhere between 3-10 pulls.
Pour the ultracal into the head mold, and let it sit. Once it is cool to the touch, you can break it open to pull out your bust.
Step 7: Step 7: You're Done!
And voila! you have a head to sculpt upon!
You will need to stand the back of the head quite a bit because the plaster gauze will leave a rough edge. You can see on mine that the alginate ripped on the forehead. All of these things are easily fixable!