When most people think of fairies/faeries they think of little butterfly winged people but where does this portrayal come from?
The image of gossamer-winged fairies is largely of Victorian origin. There are some pre-19th century examples of fairies with wings, but these are fairly different than the more familiar depictions - Henry Fuselli's rendition of Puck, or Robin Goodfellow (c. 1790), based on Shakespeare's A Midsummer Night's Dream, for example, has bat wings. Nicola Bown in Fairies in Nineteenth Century Art and Literature 47 notes:
Pictures of winged fairies appeared at the end of the eighteenth century: the first example is Fuseli's Puck (1790), whi has bat's wings. Thomas Stothard's illustrations for a 1798 edition of The Rape of the Lock were the first to give fairies butterfly wings, and these established the convention for nineteenth century artists. As the frontispiece to Canto III (fig. 5) shows, Stothard's fairies are clearly derived from putti and are generally drawn from Raphael and Murillo, yet he has also followed the textual source, both in giving them insect wings and in making them invisible, as described in these lines from Canto II:
Some to the sun their insect wings unfold,
Waft on the breeze or sink in clouds of gold;
Transparent forms, too fine for mortal sight,
Their fluid bodies half dissolved in light.
The image was further popularized by the Cottingley Fairies photographs used by Sir Arthur Conan Doyle to illustrate an article (1920), and later his book The Coming of the Fairies (1922).