In spiritualism, paranormal literature, and some religions, materialization (or manifestation) is the creation or appearance of matter from unknown sources. The existence of materialization has not been confirmed by laboratory experiments. Numerous cases of fraudulent materialization demonstrations by mediums have been exposed.
In the early 20th century a series of exposures of fraudulent activity led to a decline of materialization séances. The poet Robert Browning and his wife Elizabeth attended a séance on 23, July 1855 in Ealing with the Rymers. During the séance a spirit face materialized which Home claimed was the son of Browning who had died in infancy. Browning seized the "materialization" and discovered it to be the bare foot of Home. To make the deception worse, Browning had never lost a son in infancy. Browning's son Robert in a letter to The Times, December 5, 1902 referred to the incident "Home was detected in a vulgar fraud."
The British materialization medium Rosina Mary Showers was caught in many fraudulent séances throughout her career. In 1874 during a séance with Edward William Cox a sitter looked into the cabinet and seized the spirit, the headdress fell off and was revealed to be Showers. On March 29 and May 21, 1874 Florence Cook in her own Home held séances with William Crookes. It was alleged that a spirit called "Katie King" materialized, however according to the author Walter Mann "Katie was a confederate introduced by Florrie Cook. It was the easiest matter in the world to carry out this trick, since the room, described by Sir William as the "cabinet", was Florrie Cook's bedroom."
Frank Herne a medium who formed a partnership with Charles Williams was repeatedly exposed in fraudulent materialization séances. In 1875 he was caught pretending to be a spirit during a séance in Liverpool and was found "clothed in about two yards of stiffened muslin, wound round his head and hanging down as far as his thigh." Florence Cook had been "trained in the arts of the séance" by Herne and was repeatedly exposed as a fraudulent medium.
The psychical researchers W. W. Baggally and Everard Feilding exposed the British materialization medium Christopher Chambers as a fraud in 1905. A false moustache was discovered in the séance room which he used to fabricate the spirit materializations. The British medium Charles Eldred was exposed as a fraud in 1906. Eldred would sit in a chair in a curtained off area in the room known as a "séance cabinet". Various spirit figures would emerge from the cabinet and move around the séance room, however, it was discovered that the chair had a secret compartment that contained beards, cloths, masks, and wigs that Eldred would dress up in to fake the spirits.
Albert von Schrenck-Notzing investigated the medium Eva Carrière and claimed her ectoplasm "materializations" were the result of "ideoplasty" in which the medium could form images onto ectoplasm from her mind. Schrenck-Notzing published the book Phenomena of Materialisation (1923) which included photographs of the ectoplasm. Critics pointed out the photographs of the ectoplasm revealed marks of magazine cut-outs, pins and a piece of string. Schrenck-Notzing admitted that on several occasions Carrière deceptively smuggled pins into the séance room. The magician Carlos María de Heredia replicated the ectoplasm of Carrière using a comb, gauze and a handkerchief.
Donald West wrote that the ectoplasm of Carrière was fake and was made of cut-out paper faces from newspapers and magazines on which fold marks could sometimes be seen from the photographs. A photograph of Carrière taken from the back of the ectoplasm face revealed it to be made from a magazine cut out with the letters "Le Miro". The two-dimensional face had been clipped from the French magazine Le Miroir. Back issues of the magazine also matched some of Carrière's ectoplasm faces. Cut out faces that she used included Woodrow Wilson, King Ferdinand of Bulgaria, French president Raymond Poincaré and the actress Mona Delza.
After Schrenck-Notzing discovered Carrière had taken her ectoplasm faces from the magazine he defended her by claiming she had read the magazine but her memory had recalled the images and they had materialized into the ectoplasm. Because of this Schrenck-Notzing was described as credulous. Joseph McCabe wrote "In Germany and Austria, Baron von Schrenck-Notzing is the laughing-stock of his medical colleagues."
In 1907, Hereward Carrington exposed the tricks of fraudulent mediums such as those used in slate-writing, table-turning, trumpet mediumship, materializations, sealed-letter reading and spirit photography. Between 8 November and 31 December 1920 Gustav Geley of the Institute Metapsychique International attended fourteen séances with the medium Franek Kluski in Paris. A bowl of hot paraffin was placed in the room and according to Kluski spirits dipped their limbs into the paraffin and then into a bath of water to materialize. Three other series of séances were held in Warsaw in Kluski's own apartment, these took place over a period of three years. Kluski was not searched in any of the séances. Photographs of the molds were obtained during the four series of experiments and were published by Geley in 1924. Human skin hairs were found on the moulds which has indicated fraud. Harry Houdini replicated the Kluski materialization moulds by using his hands and a bowel of hot paraffin.
Erlendur Haraldsson investigated one of the Hindu swamis, who are associated with frequent and widely accepted claims of materializations of objects or substances, namely Gyatri Swami, and reached a negative conclusion regarding his claims. 
Indian gurus Sathya Sai Baba (died 2011) and Swami Premananda have claimed to perform materializations. Spontaneous vibuthi (holy ash) manifestations are reported by Baba's followers on his pictures at their homes. Skeptics have suspected the materializations of Sathya Sai Baba were fraudulent and the result of sleight of hand tricks. The magician P. C. Sorcar wrote Sai Baba's vibhuti feat was a "common trick" conjured with an ash capsule.
- Mary Roach. (2010). Spook: Science Tackles the Afterlife. Canongate Books Ltd. pp. 122-130. ISBN 978-1847670809
- John Melton. (2007). The Encyclopedia of Religious Phenomena. Visible Ink Press. p. 96. ISBN 978-1578592098
- Donald Serrell Thomas. (1989). Robert Browning: A Life Within Life. Weidenfeld and Nicolson. pp. 157-158. ISBN 978-0297796398
- Harry Houdini. (2011 reprint edition). Originally published in 1924. A Magician Among the Spirits. Cambridge University Press. p. 42. ISBN 978-1108027489
- John Casey. (2009). After Lives: A Guide to Heaven, Hell and Purgatory. Oxford. p. 373. ISBN 978-0199975037 "The poet attended one of Home's seances where a face was materialized, which, Home's spirit guide announced, was that of Browning's dead son. Browning seized the supposed materialized head, and it turned out to be the bare foot of Home. The deception was not helped by the fact that Browning never had lost a son in infancy."
- Sherrie Lynne Lyons. (2010). Species, Serpents, Spirits, and Skulls: Science at the Margins in the Victorian Age. State University of New York Press. p. 100. ISBN 978-1438427980
- Alex Owen. (2004). The Darkened Room: Women, Power, and Spiritualism in Late Victorian England. University Of Chicago Press. pp. 70-71. ISBN 978-0226642055
- Walter Mann. (1919). The Follies and Frauds of Spiritualism. Rationalist Association. London: Watts & Co. p. 89
- Georgess McHargue. (1972). Facts, Frauds, and Phantasms: A Survey of the Spiritualist Movement. Doubleday. p. 113. ISBN 978-0385053051
- Janet Oppenheim. (1985). The Other World: Spiritualism and Psychical Research in England, 1850-1914. Cambridge University Press. p. 19. ISBN 978-0521265058
- Paul Kurtz. (1985). A Skeptic's Handbook of Parapsychology. Prometheus Books. p. 29. ISBN 978-0879753009 "Florence Cook was caught cheating not only before her séances with Crookes but also afterward. Furthermore, she learned her trade from the mediums Frank Herne and Charles Williams, who were notorious for their cheating." Also see M. Lamar Keene. (1997). The Psychic Mafia. Prometheus Books. p. 64. ISBN 978-1573921619 "The most famous of materialization mediums, Florence Cook-- though she managed to convince a scientist, Sir William Crookes, that she was genuine-- was repeatedly exposed in fraud. Florence had been trained in the arts of the séance by Frank Herne, a well-known physical medium whose materializations were grabbed on more than one occasion and found to be the medium himself."
- Richard Wiseman. (1997). Deception & Self-Deception: Investigating Psychics. Prometheus Books. pp. 12-23
- M. Brady Brower. (2010). Unruly Spirits: The Science of Psychic Phenomena in Modern France. University of Illinois Press. p. 120. ISBN 978-0252077517
- Carlos María de Heredia. (1922). Spiritism and Common Sense. P. J. Kenedy & Sons. pp. 186-198
- Donald West. (1954). Psychical Research Today. Chapter Séance-Room Phenomena. Duckworth. p. 49
- Georgess McHargue. (1972). Facts, Frauds, and Phantasms: A Survey of the Spiritualist Movement. Doubleday. p. 187
- Gordon Stein. (1996). The Encyclopedia of the Paranormal. Prometheus Books. p. 520. ISBN 978-1573920216
- Frank Harris. (1993). Debates on the Meaning of Life, Evolution, and Spiritualism. Prometheus Books. p. 77. ISBN 978-0879758288
- Hereward Carrington. (1907). The Physical Phenomena of Spiritualism. Herbert B. Turner & Co.
- Clément Chéroux. (2005). The Perfect Medium: Photography and the Occult. Yale University Press. p. 268. ISBN 978-0300111361
- D. Scott Rogo. (1978). Mind and Motion: The Riddle of Psychokinesis. Taplinger Publishing. pp. 245-246. ISBN 978-0800824556
- Michael Coleman. (1994). The Kluski moulds: a reply. Journal of the Society for Psychical Research. Volume 60: 98-103.
- Massimo Polidoro. (2001). Final Séance: The Strange Friendship Between Houdini and Conan Doyle. Prometheus Books. pp. 71-73. ISBN 978-1573928960 "At the time Houdini didn't press the argument further, but later on, experimenting with paraffin, he found no artifice was needed to duplicate Kluski's molds. As a series of pictures for a newspaper of the time shows, he immersed his hand in the hot paraffin, let it dry, and then carefully removed the hand from it. When one experiments with this technique, one realizes that it is not the plaster cast that has to be removed from the thin wax mold, which would be impossible to do without breaking the mold. One almost forgets that what has to be removed is the living hand, possibly the best-suited object to slip out of a mold without damaging it. In fact, a real hand is even more effective than any other artifice dreamed up to substitute for it. First, the paraffin doesn't stick to skin, only to quite long hair. Nonetheless, if one moves the fingers very slowly, one will realize that every small bit one pulls out will gradually allow the rest of the hand to be removed; that's similar to what happens when one pulls off a tight glove."
- Haraldsson, Erlendur (1994). Report on an Indian Swami Claiming to Materialize Objects: The Value and Limitations of Field Observations (PDF). Institut fur Grenzgebiete der Psychologie und Psychohygiene: Journal of Scientific Exploration Vol.3 No.3. pp. 381–397.
- Sathya Sai Baba Miracles depicting photos of miracles associated with Sai Baba
- Mick Brown: The Miracle In North London. In: The Spiritual Tourist. A Personal Odyssey Through the Outer Reaches of Belief. 1998, ISBN 1-58234-034-X, pp. 29-30
- Prinella Pillay: Divine blessing: It's a miracle, says family. In: Post (South African newspaper), 17 March 2004
- The Sunday Times (South Africa): House of Miracles. 24 March 2002
- The Life and Death of ‘Living God’ Sathya Sai Baba by Ryan Shaffer
- P.C. Sorcar: "Baba's a bad trickster"
- Joseph McCabe. (1920). Is Spiritualism Based On Fraud? The Evidence Given By Sir A. C. Doyle and Others Drastically Examined. London: Watts & Co.
- Georgess McHargue. (1972). Facts, Frauds, and Phantasms: A Survey of the Spiritualist Movement. Doubleday. ISBN 978-0385053051
- Frank Podmore. (1911). The Newer Spiritualism. Henry Holt and Company.
- Massimo Polidoro. (2003). Secrets of the Psychics: Investigating Paranormal Claims. Prometheus Books. ISBN 978-1591020868
- Harry Price and Eric Dingwall. (1975). Revelations of a Spirit Medium. Arno Press. Reprint of 1891 edition by Charles F. Pidgeon. This rare, overlooked, and forgotten, book gives the "insider's knowledge" of 19th century deceptions.
- Albert von Schrenck-Notzing. (1923). Phenomena of Materialisation. Kegan Paul, Trench, Trubner.
- Heather Wolffram. (2009). The Stepchildren of Science: Psychical Research and Parapsychology in Germany, C. 1870-1939. Rodopi. ISBN 978-9042027282