Ectoplasm (from the Greek ektos, meaning "outside", and plasma, meaning "something formed or molded") is a term coined by Charles Richet to denote a substance or spiritual energy "exteriorized" by physical mediums. Ectoplasm is said to be associated with the formation of spirits (by researchers); however since World War II reports of ectoplasmic phenomena have declined and many psychical researchers doubt whether genuine cases ever existed.
The term Ectoplasm is used in Parapsychology and is taken to denote a substance which occurs allegedly in a medium of the body openings. Ectoplasm is supposed to be a gray-white or pink, frothy or slight pulling threads. According to reports by Richet and other scientists of the time it could in more complete materializations be fixed as well. Ectoplasm (later known as Teleplasma) was very sensitive to light and therefore barely visible under normal conditions, only in dark or illuminated with red light areas. Skeptics consider ectoplasm rather than "photophobia" - they think that if it were gauze , which could be used as ectoplasm only in the dark, because it is recognizable in light as gauze.