Edible

Karo syrup (light corn syrup), black-cherry Kool-aid powder and smooth
peanut butter

4 parts liquid glucose, 1 part water, chinese red food colouring

Ruby orange juice, with the bit strained out (sprays nicely)

Corn syrup, red food dye, a little blue & green food dye.

From murr@vnet.net:
MB2 Blood Formula

Flour Base:

7.5cc to 10cc plain all purpose flour per cup (250cc) of water. (7.5cc =
1/2 level tablespoon , 10cc = 2 level teaspoons) Mix flour into water
completely (no lumps) before heating. Bring to boil then simmer for 1/2
hour. Stir frequently.

Let cool before adding food color. Stir in any surface scum. Makes a
good base for stage blood. Slightly slimy. Fairly low surface tension.
Soaks and spreads well.

One cup batch of MB2:

1 oz (29cc) Red food coloring (Durkee (R) brand or equivalent) 1/8
teaspoon (.6cc) green food coloring (Durkee (R) brand or equivalent) Add
flour base described above to a total of one cup (250cc).

This is both much more realistic and simpler than the old Karo (R) corn
syrup, Hershey's (R) chocolate syrup and food coloring based formula.
There is no sugar and very little food in the MB2 formula so it's
probably less attractive to insects. Shelf life is fairly short (days)
at room temp. Does not go rank but ferments a bit and looses viscosity.
I have not tested refrigerated or frozen storage. This formula will
temporarily stain skin. Seems to wash out of cotton cloths OK.

Inedible:

Adding a little washing-up liquid to any of the above may make it easier
to wash out of costumes.

Adding blue washing detergent has been suggested - it makes the blood
easier to wash out, and darkens the blood. Be careful of this, washing
detergent can cause severe allergic reactions.

Commercial Stageblood

(From Rich Williamson of Pierre's Costumes, http://www.costumers.com/
NJ, USA, 1-888-PIERRE1)

Ben Nye

Best all around blood. Flows very well. Color is deep and shows up well
on video or film. A little too dark for black actors. Moderately
washable. Bonus: Edible, and mint flavored. Also available in Thick
blood (excellent) and dried scab (browner and older looking) Ben Nye
also has a full line of product in his Moulage line...(for EMT and
Disaster training) Geleffects can creat great wounds without messing up
clothing (product is made ahead of time and is dry once used, you can
spray glycerine to "freshen" or moisten it). He also provides a great
product. Dried blood powder. It is a very economical way to go...you can
splash it all around or stain clothes with it...designed to simulate
horrific crash scenes in emergency training exercises.

Mehron

The worst on the market....too light....too runny...looks like watery
strawberry pancake syrup. Don't waste your time

Kryolan

Excellent products...they have blood that dries to the touch (great for
clothes) Eyeblood (cry tears of blood)...their film blud is great for TV
and video...it has a yellow pigment in it that reflects nicely under
lights.it also smears very realistically. Film blud is available in
arterial (light color) and venous (darker). Frankly they have many more
products...they are the most comprehensive carrier of blood...I just
don't need the others...but I can get them if someone needs them.

Reel

Fred has the best bloods on the market. He is a little know secret. He
has been a make-up artist for the last 30 years. He works on major first
run movies. His blood is available in "original" (great bright color,
washable, runs well, great all around blood for most scenes and skin
types) "Lung" (brighter for either gruesome spurting scenes, or use with
darker skinned actors. Bubbles very well for gushing wounds), and aged
(darker for that "I cut myself 15 minutes ago and it hasn't stopped
flowing yet" look. He also provides thick blood. Fresh (great brush
burns and scrapes...stays in place), aged (older scabby look) and old
dried (dark brown look) ...mixing the 3 together in appropriate streaks
and blobs makes the MOST realistic looking wounds for TV and Film

(BTW Reel is the best source for custom tattoo painting systems. It is a
cross between real tattoos, stencils, and an alcohol based painting
system. There are over 5000 styles avail. ranging from gang to prison to
biker to tribal. They can't be discerned from real ones up close...even
when you rub on them)

The most washable of all bloods is Reel