Many brands of stage blood are coloured with FD & C Red #40 food colouring. Here are a few points about non-staining blood.

Many brands of stage blood, the kind often used in simulations, are coloured with FD & C Red #40 food colouring. This azo dye has a tendency to stain some types of surfaces. You can make non-staining blood for simulation by mixing a water-based lubricant like KY Jelly with red flocking. Flocking is made from short, fine, synthetic fibres, and can be purchased from special makeup effects suppliers. Glycerin added to the blood will make it flow and keep it from drying out. Add tiny amounts of yellow, brown, black, or blue flocking as necessary to adjust the colour of the blood. Apply the blood with a small stainless steel makeup spatula. One of the nice properties of this blood is its ability to stick to silicone prosthetic appliances and some other types of slick surfaces. This type of blood was used in the 2011 movie Water for Elephants.

A few points about non-staining blood:

• Getting the colour right takes a bit of experimentation. I suggest filling several small containers with the colours you need (venous blood, arterial blood, or old blood). Adjust the consistency just before use by adding glycerin.
• Do not compound any of this blood in a windy area and be very, very careful not to spill any of the flocking. Dry flocking is very light and will easily be blown around by a light wind.
• This blood does not flow or dry in the same way that stage blood does.
• If you have very good eyesight AND you look at this blood up close or with a magnifier you might be able to see some of the fibres. This is most likely not a problem for most simulations.
• Keep this away from the eyes. The tiny flocking fibres and the glycerin may cause irritation.
• Although the colour fibres in this blood will not stain, the water-based lubricant base may stain some types of surfaces. Test a small area first.