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Washes out decently, although you may have to soak it. If so, don't let it dry out, but soak it ASAP. Sometimes washes out with more than one wash.
Advice
For tricky scenes with a lot of blood, professional blood looks a lot better. Detergent turns up a little red and pinky sometimes.
Applications
Body and hand packs
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Ones we bought online for Julius Caesar: http://www.gravityandmomentum.org/stage-blood/blood-caplets/
These ones are awesome and tasty, but you may need more than one for a good effect. Some saliva is still needed for rivers of blood to gush forth. Otherwise may only be a trickle.
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