I got called in to do sp/fx (that's "industry" for special effect makeup) the day before a shoot when the regular sp/fx guy had an emergency and couldn't make it. The makeup guy called me and asked if I could step in for him, since we've worked together before and I could keep continuity with his work.
The script called for the actor, in a state of mental anguish, to torture herself by pressing a razor blade into her palm. Not to slice it up a lot, just a little. Since this was being shot with hi-def equipment the cut had to look like a real cut, which meant thin layers.
I would have preferred to create a silicone appliance that she could actually slash up, put a little blood pack beneath it so they could shoot it all in one, but there was no time for that luxury. So I relied on the lo-tech old school method of latex, paint, and runny blood, and great acting, and we got it in one take.
I don't have access to the footage, as it's still in post production. The effect was so realistic that the producer, who was watching on the monitor, turned a funny shade of green and had to take some deep breaths before the cold sweats went away. So, not for the squeamish!
Step 1: Materials Needed & Preparation
Injury Stack Greasepaints
Small Palette Knife
Small Palette or Disposable Non-paper Plate
Runny Stage Blood
Small Paint Brushes (2)
Witch Hazel or Other Oil-Free Toner
Small Glass or Metal Bowl
If you don't have an injury stack or injury wheel, you can use greasepaints in red and black. If your trauma needs a little bruising, you'll also want blue and yellow paints, or a bruise wheel.
Begin by cleansing the area with toner to remove any excess oils and perspiration.
Step 2: Add Some Skin Tone to the Latex.
(BTW: test first for latex allergy if you have any doubts.)
It is important for sanitary reasons that you don't dip your brushes into product while it's in the bottle, but instead to dispense it onto a palette (or styrofoam or plastic plate). Cross-contamination can cause all sorts of yukky things to grow in your materials, and if you noticed, latex isn't exactly cheap (about $17 for a liter). This is even more important when it comes to greasepaint, and will be discussed in that step.
I have put a bit of runny blood in the lid here for the picture, but I would just allow a single drop to fall into the latex. Fake blood is worse than mustard in its ability to travel and stain, so use only what you need.
Stir the blood into the latex with the palette knife. *DON'T* use your brush; latex does not like to come out of nice brushes.
If you get it too dark like I did, pour out another drop of latex and use the mixture to tint it. It will dry a little darker, so err on the side of less tint.
All right: this is ethnically biased for pasty caucasians. If your skin is yellowy, you may be able to use just the latex without the tint. If you have darker skin, you'll need to use a little bit of ground eyeshadow or even a bit of instant coffee (mix with a drop of water first) to color the latex. While it's liquid, you can mix a water-based substance, including watercolors, into the latex. If you use anything oil-based, like foundation, it won't set up properly. But the runny blood will work for a lot of people, so try it and see how that goes.
Step 3: Lay Down a Stripe of Latex.
Notice we are touching the skin with the palette knife. When you are happy with the stripe, let it dry. Don't allow the latex to touch itself or else it will stick to itself and you'll have to do it over.
Clean the knife with alcohol or the toner if it's got alcohol in it. Don't use it on the skin again, yet.
Instead, get out the injury stack and, using the clean palette knife, scrape out a very small amount of red, maroon, and eggplant onto the palette. You only need a little bit. Also place a very small amount of baby powder on the palette.
More on cleanliness: a pan of greasepaint might as well be labelled "petri dish". Never dip a brush or sponge directly into anything you're not going to throw away that day, because you'll be transferring all sorts of germy bacterial things into it. Greasepaint is a loving medium perfect for hosting loads of creatures.
On a side note, somewhat related to this: if you currently use a cover-up stick on your zits, and you notice that the more you cover them the worse they get... well, is it a surprise? Use a clean brush or a cotton swab to remove product from your cover-up stick rather than touching it directly to your face to avoid getting zit germs back on your cover-up product. Bluck!
Since I use my paints on multiple people, I have to be very careful about avoiding contamination. In the case of this model (my daughter), I happen to know that she has recently recovered from a fungal infection of the hands. However, if I didn't know that and wasn't using appropriate precautions, my greasepaints would now harbor that fungal infection and pass it to everyone I used it on from here on out.
Since it takes a while to incubate, it could be weeks before an actor who got their eye blacked from my handiwork developed itchy scaly weepy skin around their eyes, and longer still before it was recognized as a fungal infection, and even longer before the treatment was over. That could ruin the actor's chance of working, and potentially contaminate other actors if the next makeup artist was slackerly. If it could be traced back to my mishandling of materials, I could be sued. So I'm extremely careful about making sure my products stay as pure as they can.
By assuming that everyone has some evil communicable disease, it's not hard to be in the habit of avoiding contamination.
Is the latex dry yet? Great! Make sure the lids are on all your products and let's move on.
Step 4: Make a Little "boat".
Carefully lift the edge on one side then the other, leaving the ends intact.
Now we exploit the sticky self-adhesive qualities of latex. On one end, push the two sides together to make a tiny triangle. Be careful to not let the rest of the latex touch itself.
Do the same on the other side.
Use one brush to dip into the baby powder. I prefer a round brush for this but it's all down to personal preference.
Liberally powder first the inside then the outside of the "boat". The color of the latex should mute down quite a bit with this step.
Step 5: Add Color.
First use the bright red to color the whole inside of the "boat".
Then the maroon to deepen the bottom.
Finally, dab spots of eggplant on the maroon, but don't be obsessive about blending it together.
Step 6: Get Gross With Runny Blood!
Using the same brush you dipped into the baby powder, load up with fake blood. The powder still on the brush is fine, may even provide realistic clotting, but don't add more powder -- talc has a greasiness to it that won't mix with the liquid blood.
Dribble a bit of runny blood into the cut. Tip hand back and forth to get the right effect, to get it to run into the crevasses.
If you get too much, lift some out with the corner of a tissue.
When satisfied, shoot your f/x scene!
Step 7: Clean Up Is Easy!
To clean your palette, place a tissue over the latex and wipe up. Use liquid soap and water.
To clean the brushes, rinse the blood out of the little bowl and add a couple drops of liquid soap. Dawn (non-ultra) is very good at getting greasepaint out of brushes. Moosh the brushes around in the soap.
Rinse things well and air-dry. Reshape the tips of the brushes before drying.
Step 8: Other Applications
First make some slashes on your face and neck.
Color to look fairly realistic. Use the yellow for a litle bruising/swelling effect if you like.
Add some sticky blood (remember to get the clothes too), and the proper expression and posture, and blend right in with the hoardes until you can make your getaway.