Kobracast can be used to make a cast of a model’s head without the mess or time requirements of alginate. Because it can be breathed and spoken through during the application, and your model is actively participating in the process, it is excellent for those who are uncomfortable with the alginate method. Once a cast is made, it can be used immediately, and doesn’t need to be filled. It makes an excellent way to make masks or pieces that need to fit the head perfectly.

Casting a head
Last Minute Man’s Kitchen created this step-by-step video of the process.
(German with English subtitles)

Partial transcript

0:01 Hello guys, welcome to „Last minutes man's kitchen“!
0:04 In this clip, I show how to create a full head-impression with KOBRACAST
0:10 My model today is Boris. We eternalize him now with his own materials.
0:19 To prepare his head, I coverd his hair with cling wrap.
0:24 If your model is really hairy, you can put some lotion on eyebrows and beard to make sure no cast 
 sticks there.
0:30 To begin, I place the first stripe of KOBRACAST from forehead to the scruff.
0:34 It's easier for the working person, if the model helps a bit, especially when you work on the
 sensible parts like eyes, ears and mouth.
0:43 And it simplifies the whole process.
0:45 I add two more stripes of KOBRACAST, again from forehead to the scruff, but sideways around the
 head, one to the left and one to the right.
0:50 It's important, that you fix all three stripes with another, on both sides!
0:55 If you're used to the material, that part also works with one long stripe that you wind around
 your model's head.
1:00 For further stabilization, I also wind a stripe around the neck.
1:04 KOBRACAST can be heated in different ways, here I used a heat gun. But you can also use hot water.
1:20 When you use a heat gut, you should always supply a bowl with water to dampen your fingers.
1:26 With moistured fingers, you can easily smoothen the Cast, without it getting sticked to your fingers.
1:32 Without water, you'll get sticky fingers very fast and instead of glueing the pieces together,
 you'll tear the Cast away from the surface.
1:40 When you realize, that the basic fixing stripes become loose while you add further stripes,
1:50 you can cut the loose stripes, tense them and fix them with another little piece of KOBRACAST.
2:37 If you're not so used to working with KOBRACAST, it's easier to work with stripes of a width of
 about 3cm (~1,2inches).
2:47 If you're an experienced Cast-worker, you can also cut out two oval pieces to close the head's sides.
2:55 Be aware, that you have to remove the stripes if they're not located properly, cause you can't
 re-heat it while it's on your model's head!
3:05 If absolutely necessary, you can carefully try to re-heat it with a usual hairdryer.
3:10 If you work with KOBRACAST for the first time, realize that it should take about 45 minutes to 
get a head-impression.
3:20 Overhanging parts of KOBRACAST can be removed with a cutter later, after the head was filled with
 crafting foam.
3:25 This way you get a result true to scale although you just created a negative-impression, meaning
 that you don't have to fill your negative mould like you have to,
3:35 when you work with plaster- alginate or silicone-forms. You can start working with the
 KOBRACAST-head right away.
4:18 For your model, it's most comfortable, if you start working in the back and make your way to the
 front, because nose, mouth and eyes are not coverd for such a long time then.
4:32 Cover the head until you reach the ear. Then place one more stripe in front of it.
4:37 For the ear itself, you should work with stripes of 1cm (~0.4inches) width, because they're more
 flexible and you can cover the arches of the ear more easily.
4:47 Unfortunately, I don't have that part on tape. :/
5:20 For the chin, you should start at the edge of the neck and add the pieces until you reach the chin's
 tip.
5:26 There you should stop and your model should hold the KOBRACAST until it has cooled down and is
 stiffened!
5:36 Meanwhile, you can put one stripe over the nose's bridge, this will be really helpful, when you come
 to connecting the parts around the mouth.
5:46 Back to the chin: apply stripes beneath the mouth and connect them to the part under the chin you
 prepared before.
5:55 It's the easiest way to get a perfect curved chin, when you cover the tip at last.
6:03 Apply KOBRACAST to the cheeks until only the lips and nostrils are uncovered and place one single
 slender stripe on the upper lip.
6:18 Then take one stripe that is wide enough to cover the whole mouth without being stretched and stick
 it to the chin-part and the upper lip-piece.
6:29 The shaping of the lips should be done by the model itself.
6:33 For the time the Cast needs to stiffen, the model should not speak or move the lips.
6:37 Afterwards, he or she can breath through the mouth and speak normally again.
6:41 Same procedure for the eyes: cover it with an unstretched part and let the model do the shaping.
7:01 At last you only have to cover the nostrils, but make sure the moth is firm, assuring your model can
 breathe through it,
7:11 what is no problem, cause the net-structure provides enough space to breathe through.
7:21 Then you can release your model.
7:45 You can breathe through it which is no problem in opposite to modelling with plaster.
8:00 To free the head from the Cast, just cut the back part from the Neck to the forehead with medical
 scissors or nail scissors.
8:16 But be careful with your model, tear the cast a bit away from the head and make small incisions to
 make sure not to hurt the person underneath or cut their hair.
8:27 Some won't be happy about that.
8:45 KOBRACAST is very flexible, it's no problem to spread it so wide, that the head within can be
 released.
9:05 Thus, Boris is loosened and his skin is still on his face and not sticked to the KOBRACAST.
9:14 I hope I could help you with this video!
9:17 Some other ones about further processing with crafting foam and glue will follow!
9:23 Enjoy working with KOBRACAST!
9:31 Yours Last Minute Man.