"Kensington Gore" (a pun on the London place and street) was a trademark for fake blood used in films and in theatre. It was manufactured by a retired British pharmacist, John Tinegate, during the 1960s and 1970s. Many varieties of blood, having various degrees of viscosity, shades and textures, were available. The name "Kensington Gore" has become a generic term for stage blood. Kensington Gore was used in the film The Shining.

It's a very popular brand in the world of stage and film drama, because its viscosity is very much like that of real blood, and much to the relief of wardrobe assistants, actually washes out very well..it has the added bonus of tasting like peppermint.

More Info: en.m.wikipedia.org