Shop fake blood costs about eight dollars for a small bottle and most of it looks like cherry syrup on camera. Benjamin Martian of Real Fake Blood Films makes a better version out of corn syrup and food colouring for roughly three dollars, then shows what to stir in to change the look.
The base takes two minutes. The variations are where it gets interesting, because fresh blood, old blood and congealed blood are three different materials and one recipe will not do all three.
The base recipe
Corn syrup, a lot of red food colouring, and one drop of blue. That is it.
The blue is the part people skip and it is the part that matters. Straight red food colouring reads as candy. Real blood is much darker and sits closer to a red-brown, and a single drop of blue drags the whole mix in that direction. A little green or yellow does a similar job. Add it a drop at a time because it goes too far quickly.
Stir with a downward motion. Food colouring floats on corn syrup and will sit in a layer on top if you just swirl it.
Test it on white before you commit
Colour in a bowl looks nothing like colour smeared thin. Keep a paper towel or an old white t-shirt beside you and drag a test streak across it every time you adjust.
If the blood beads up into droplets on skin rather than spreading, stir in a little dish soap. That breaks the surface tension and it will lie flat and wet-looking instead.
Making it opaque
The base is translucent. Real blood is not. Mix small test amounts rather than dosing your whole batch, because these are hard to undo.
| Add | Result |
|---|
| Cornstarch | Opaque and slightly matte. Add gradually or it clumps |
| Cocoa powder | Much darker. Good for old or dried blood |
| Chocolate syrup | Darker and still glossy. A classic for a reason |
| Non-dairy creamer | Clouds it into a stylised, film-looking red |
| Flour | Thick and matte, that eighties horror look |
Any of these will shift the colour, so top the food colouring back up afterwards.
Gel blood for detail work
Gel holds its shape instead of running, which is what you want for a wound that has to stay put through a party or a scene.
Unflavoured gelatin gives the best congealed look. Hair gel is less malleable but works. Red gel toothpaste is a decent option and has the advantage of being edible. Petroleum jelly gives a thick coagulated finish, though it needs dish soap in it or it beads badly on skin.
Clots and texture
Tear up toilet paper and stir it in for clumpy blood. Cotton balls pulled apart create nastier stringy masses that clump and tear. Clear school glue thickens into chunks and dries more than the others do, which is useful if you need it to stop moving.
What it will stain
Red food colouring stains fabric, grout, unsealed wood and light carpet, and corn syrup makes it stick around long enough to soak in. Treat every surface as at risk and lay down more paper towel than feels necessary.
On skin it washes off with soap and warm water, though a strong mix can leave a pink tint for a few hours. Test on an inner arm first if it is going anywhere near a face. Get it out of clothing quickly with cold water, because warm water sets it.
Keep a bowl of water and a rag next to you the whole time. You will be washing your hands constantly and walking to the sink with blood on them is how it ends up on a door handle.
Making a whole costume? A no-sew cheesecloth ghost and sewing on a patch cover the other jobs that come up in the last week of October.