Step 1: What You Need
You will need the following things
a Polystyrene head (ebay)
10kg NewPlast modeling clay, this is a clay that is reusable like plasticine
20-25kg Crystacal R Plaster (this is a hard plaster, much harder than plaster of paris, do not use plaster of paris for this its too soft)
Jute Scrim (burlap)
Hot Glue Gun
Large Marbles or other round objects to make the key points.
1-2 litres of Liquid Latex
100ml Latex Thickener.
Talcum powder (Talc)
Plumbers Epoxy Putty (for mold repairs)
AirBrush Propellant or compressor.
Artists Paint Brushes.
Washing Up Liquid.
Tubs to mix paint in and store it for a short time.
Sheet Metal pieces
Depending on the mask your doing you may also need some foam, i found buying a cheap yoga mat to chop up works well, i used this to fill the dreadlocks.
Step 2: Sculpting the Design
Take your polystyrene head and build up layers of Newplast so that it matches the dimensions of your own head or slightly larger as the latex will shrink slightly in the mold.
Now you can start sculpting your mask design, mine is the predator so i just added layers on and manipulated them to the shape i needed.
its important to note that you should try and keep things simple, if you have complex parts on the design you will need to cut these off and mold them on there own.
Step 3: Preparing for the First Plaster Stage
you need to decide where you want your seam line to be, somewhere it wont show too much or can be covered by paint.
when you know where your seam line will be hammer in pieces of steel to form a platform, overlap each piece and make sure they are in there fairly deep as they will need support the weight of the plaster.
Hot Glue the steel pieces together to make the structure stronger.
Roll out some newplast about half an inch thick and cut it a few inches wide and lay it on top of the steel pieces nice and tight to the sculpt
then make some walls around the edge of the newplast about an inch and a half high this will hold the plaster in.
Make a well down the bottom fairly deep, as the plaster will drip down and this well will catch it.
Now add your round objects to make the key points, if your using marbles push them in just over half way in. I ended up using Xmas Baubles cut in half.
You should coat the round objects in Vaseline to make them easier to remove from the plaster.
you can put a thin layer over the whole sculpt of Vaseline, as long as this doesn't effect the detail of the mask.
Step 4: Adding the First Stage of Plaster
make sure you cover everything in plastic where your working esp the floor
Ok first off mix a thin mixture of plaster a little thicker than water, like a very thin syrup, this is called the beauty coat. The beauty coat is suppose to pick up all the detail of your sculpt. pour this slowly over the sculpt, using the paint brush (gently) move the plaster over it from the well, keep doing this until it starts to thicken on its own and sticks to the sculpt.
now mix up another batch of plaster to a more creamy consistency and pour it over the mold, using the brush work the plaster over the sculpt until it starts to stick and go off.
do another mix the same as above and do the same again.
once that is on there, take your Jute Scrim (burlap) and lay a layer of it over the plaster
put a creamy mix over the Jute Scrim, add another layer or Jute Scrim, do this for about 4 layers of Jute Scrim this will strengthen the mold.
Now add 2 more creamy layers of plaster and that should be all you need.
NOTE: make sure you have an equal thickness of plaster over the whole sculpt, between an inch to an inch and a half or more if you can afford the plaster. look out for weak points, on mine it was the bend on the seam line which i will show you later what happened.
Step 5: Preparing for Stage 2 of the Plaster
then peel off the newplast the plaster and the round objects used to make key points.
Now we need to repair the sculpt where the pieces of steel cut in.
then cover the plaster from stage 1 with Vaseline this will stop the plaster from stage 2 sticking to stage 1
add a couple of wedges of newplast to the edges of stage one, these will become pry points to separate the mold later on. do about 3 of these, one at the top, one on each side of the mold.
Now we need to build walls out of newplast to contain the plaster.
Step 6: Plaster Stage 2
The a couple of creamy coats then some Jute Scrim (Burlap) then plaster and so on for about 4 layers the another 2 layers or more of just plaster until its between 1 and 1 and a half inches thick at least.
then let this set, this shouldn't take too long but i would leave it for a few hours to make sure its well set.
Step 7: Seperating the Mold and Cleaning Up
Using a large strong screw driver or bar, pry the mold apart carefully.
NOTE: you will see on the pictures there's a big crack in my mold this was due to a mistake i made when doing stage 1, i put key points on the top of the mold and also on the front of it, so when i cast stage 2 i managed to get them stuck together which i didn't notice and when i went to pry them apart it cracked the mold.
now you need to remove the polystyrene head and the newplast from both sides of the mold.
you will need to use the dental pick to pick out the bits from all the detailed parts. this will need to be done to all of the mold both halves, make sure you get all of it out.
Step 8: Latex Time
OK there is 2 ways to do this
1) you strap both parts of the mold together and then pour a little unthickened liquid latex in to the mold then swish it all around the mold and leave it until set, then repeat for at least 10 coats if not more, allowing the latex to pool in parts you want to be thicker.
and this is the way i did it which was because i had a gap in my mold due to the damage to my mold.
Paint both sections of the mold with a layer of thickened latex making sure you work it in to all the details. let this set and then do it 3 or 4 times more to make it thick enough. making sure you paint over the edges slightly then put the 2 halves together with latex between them.
now leave the whole love at least 24 if not 48 hours to set as much as possible, then de-mold it and leave it for another 24 hours to dry out some more.
then its ready to de-mold, just pull the mold apart and carefully pull out the latex.
Step 9: Creating the Extra Parts
some of these can be cut in half like the mandibles and the big teeth, then we just build a wall around them out of newplast and pour plaster over them to form the mold.
then put thickened latex in the mold, do this a few times until the right thickness.
for the dreadlocks i just rolled out some newplast, covered it in Vaseline, i then paint on a mix of thickened latex and black acrylic paint, when this is dry i do a coat of normal thickened latex. you could dip the dreads in latex to coat them but i found this hard as i had no where to hang them up to dry.
when its all dried put talc on the outside and pull it back so its now inside out, making the outside black. fill this with little squares of the foam from the yoga mat then put a little latex on the end to seal it shut.
Step 10: Preparing to Paint
On all the parts trim off the excess latex from the seam lines using some sharp scissors, get as close as you can without cutting the main part of the mask.
Using a Dremel with a polish wheel run it over the seams where you just trimmed, this should remove small amounts of latex, do this until its flat to the mask.
Now i put latex on the base of the mandibles and using masking tape to hold them on the mask until the latex is set
do not stick the teeth in yet they need to be painted later.
Step 11: Time to Paint It
to mix up the paint is fairly simple, you mix the required Acrylic paint until you have the right color required, then pour in latex 1 and a half times the amount of paint. Now you need to add the ammonia until the paint is a watery consistency, this is important because if its too thick it will clog up the airbrush.
NOTE: when using this paint you should be wearing a mask as breathing in the ammonia is really bad for you.
First off you need to paint on the base coat, this will be the main color of the mask in most cases, in this case i used an off white (Antique White), you will need to spray the whole thing which may require a couple of coats to cover the color of the latex.
Once this is dry you can move to the next color, each coat should dry fairly fast as they are thin.
Next color is Yellow, sprayed round the back, and around the top of the head and inside the eye sockets.
next color is the red/brown which is sprayed over the yellow but leaving some of it showing, also spray a few spots along the edge of the yellow.
next is the darker brown, again spray this over the red/brown but leaving some of it showing again, also spray a few dots like before.
Last color is the black, this has to be sprayed in almost triangle shapes, also again a few spots like before.
the teeth should be sprayed separately then stuck on afterward.
Spray them white, then the base a watered down yellow (using ammonia to water it down) to about half way, then using a watered down brown (using ammonia to water it down) on the base.
the quills can be made from cocktail sticks coated in black latex (black acrylic paint mixed with latex) then stuck on using the same mix.