The Origins of Wonder
This full-deck false shuffle consists of fanning half of the deck in each hand and apparently meshing the cards of the fans together. In reality, one fan is slipped in its entirety under the other and the cards are squared. Henri Decremps described this shuffle in Testament de Jérôme Sharp, 1786; see Jean Hugard's English translation in Gibecière, Vol. 12 No. 1, Winter 2017, p. 138. In later years, this shuffle was performed in a more flourishy style by card manipulators.
The false shuffle was reported also to have been used by card cheats; see the anonymously authored Les misteres du pharaon dévoilés, c. 1802 (see Lori Pieper's English translation in Gibecière, Vol. 11 No. 2., Summer 2016, p. 103).