Inside-out

This little phrase is as descriptive as the similar if much earlier phrase, ‘upside-down‘, in that it originally just meant ‘with the inside on the outside’. That’s how it was used in the earliest known citation, which is from the account of the life of the 16th century clown, Richard Tarlton, titled Tarlton’s Jests, circa 1600. The citation is in the form on a stage direction for one of Tarlton’s comic characters:

Could you turne him inside out,
You would presentlie see,
Squeaking, &c.
He is a more true begotten foole
Then ever I bee.

‘Inside-out’ has become the name for an architectural style. This originated with the Pompidou Centre in Paris, designed by Renzo Piano and Richard Rogers in 1977. The building was innovative in that it was amongst the first to put features that are usually hidden, like the escalators and pipework, on the outside.

We now often use the extended form ‘to know something inside out’, that is, to know it in great detail, from all possible perspectives. This variant of ‘inside out’ is known in print from at least 1800; for example, this piece from The Dramatic Works of Baron Kotzebue, which was translated from the original German and published in New York in 1800:

“We have been in so many holes and corners together, that you know me both inside and out, as well as your own hammock.”