Sheet metal working

The last entry is le développé de la pièce, the part laid out flat before anybody cuts it, and the noun in it keeps a physical sense that English has lost. Développer was assembled from dé- and the old stem voloper, to wrap, so the verb meant to take the wrapping off, to unroll. Its exact opposite was built on the same stem with the other prefix: envelopper, to wrap a thing up, which reached us as « envelop » and as the « envelope » on the desk. English borrowed both and kept the wrapping in one of them only. « To develop » now names what a firm does to a product, what a photographer once did to a film and what a plot does in a novel, and nothing is unrolled in any of them. French kept the literal branch alive in exactly this trade: le développé is the unrolled shape, and la longueur développée is its length, measured along the metal as though every bend had been opened out again. A workshop here says « the flat pattern », and the picture of unwrapping has gone altogether.