Introduction: How to Create a Realistic 'Bleeding-Knife' Effect


Stuart here from

This video shows you how I created a realistic 'bleeding blade' to simulate skin cutting for a TV show I did a few weeks back.

There was no time or budget to make a fake chest, and I was not sure where the camera would be so I had to make it work from every angle, make it safe and make it quick. I recreate the process for you here. 

Please leave comments or get in touch if you have any questions!


Check out my new blog where I will be posting other tutorials, articles and makeup FX goodies:


srhadaham (author)2010-11-17

the effect looks awesome, and made me cringe every time.

frarugi87 (author)2017-12-01

Just came here today and... This is horrible............ Really horrible :P

ElvisE2 (author)2016-05-15

Is this cheap to make how much was it?

jsvitlik (author)2012-04-21

Nice!! instead of making a syringe, I made a little chamber inside the knife, and added a little push button in the hole. so if i wanted to make it bleed, i pushed the button which squeezed the plastic chamber and out comes the blood! Just a simple modification so you can do it in front of your friends without bringing around a syring and tubing everywere xD

HugAHunterL4D (author)jsvitlik2012-07-06

Wow! How did you do that?

gl0rious (author)2012-01-29

step 1:
cut self/sibling/friend/other with knife
step 2: done

08motooley (author)2011-08-27

looks like it could be quite good on stage we were going to have a really dramatic scene in drama class where someone committed suicide with a knife but i was having trouble with it thanks for this

dylankunaikennedy (author)2011-05-30

haha ironic that just yesterday i accadentally cut myself with a hobby knife lol

SP Tutorials (author)2011-03-05

Hey im totally going to make this but where did you get the syringe. i have actually been looking for one of those for awhile. i wanted to make bledding effects like getting knifed in the face or something. please responde asap. thanks

stuartbray (author)SP Tutorials2011-03-06


Try searching 'Laboratory Supplies', '100ml syringes', 'Vet Supplies' and 'Large Hypodermic Syringes'.

Most syringes for general medical use are much smaller volume syringes, so to hold this amount of liquid, you may need a vet suppliers or laboratory equipment supplier.

You'd be surprised how commonly these things are used, for all kinds of industry. Think any kind of work where accurate measurement of fluids such as ink cartridge refilling, etc.


SP Tutorials (author)stuartbray2011-03-06

thanks dude u r freaking amazing. keep up the great prop making.

Hephestus (author)2011-02-01

if you use liquid latex and put a thin covering over the part you wish to cut, when you move the blade away it would leave a mark where you ripped the latex looking more realistic to the viewer.

bubble36 (author)2011-01-08

How come the blood looked brown?

stuartbray (author)bubble362011-01-08

Hi Bubble

He really does, doesn't it?

Well, the blood I used was a sugar syrup blood (as many of them are) and was quite orangey-yellow.  I though it may also have been a little thick to pump easily down the blade.  I was worried it may not flow quick enough as the gag need to be quick to be most effective rather than a lingering closeup which may reveal the trick, so I added a little water.

The thinned blood ran easily, but where it was thinner at the top of the flow, it revealed my pasty-white skin and the blood colour as a result (thicker pools of blood appear darker).  Real blood is not actually that translucent, rather it is opaque so would not reveal the pale skin underneath so readily.

Also, I was shooting under fluorescent lights and these have a blue tinge which combined with the orangey-yellow blood makes for a brown colour. 

I am going to get a better camera with improved white balance (and HD) to help this issue.  Good point, though!


bounty1012 (author)2010-12-09

Wow, this really brought up the notch for those other fake blood syringe pump effects. Its looks very realistic. I might have to build one for next halloween.

jimsmith1370 (author)2010-12-09

Outstanding! (author)2010-12-05

Great vid,

J-Manoo7 (author)2010-11-18

NICE. 5*
Blood reminds me of BBQ sauce. Yummy.

zascecs (author)J-Manoo72010-11-21


J-Manoo7 (author)zascecs2010-11-21

hmmm... it appears I have a BBQ stain on my shirt.. hahaha

zascecs (author)J-Manoo72010-11-21

haha...ha.... ha..

Mr.Sanchez (author)2010-11-21 detailed...

nouserr (author)2010-11-21


Roceifin (author)2010-11-20

wicked job!

lifetaker1000 (author)2010-11-19

i gotta say man you have alot of patience, cause this looks like alot of work to me. lol

stuartbray (author)lifetaker10002010-11-19

Only took a morning. It is my day job, so not a bad way to get paid. Waiting for the paint to dry properly took the longest, but that can be an overnight job while I sleep!


lifetaker1000 (author)stuartbray2010-11-20

true true. i was just like hmmmm. wayyyy too many steps for me. lol

nickodemus (author)2010-11-18

Very convincing! Excellent work!

Tape-structable (author)2010-11-17

Video was greatly executed. And I also agree with srhadaham. I cringed with the first cut! It looks like near the end, the blood thinned? It wasn't as thick and the skin was more visible. The first cut at the end of the vid was very convincing since the blood was really on there, and It looked like there could be a cut under.

Yeah, I played around with thinning the blood down and ran out f the thicker stuff. I think the thin stuff flows better, but is not dense enough. Real blood is pretty opaque despite being runny.


kelseymh (author)2010-11-17

Very cool! Good video. I especially like the use of overlay text describing each step, all the way through, it makes it somewhat more accessible (second-channel audio description can be very expensive).

stuartbray (author)kelseymh2010-11-17

He he..thanks

I did a voice-over before, but felt this video did not need it as it was all so close-up, plus it often takes longer to say what can be seen in a few seconds of pause-able video.

Also, I sound like I have been awake for 72 hours when I hear my own voice.


About This Instructable




Bio: I create and teach makeup effects and prosthetics for a living. I love The B52's, good sarcasm and boring things like history, science and ... More »
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