(n.) the rustling sound made by silk

Proof, yet again, that there really is a word for everything came today in the form of the word scroop, the name of the soft rustling sound made by silk.

That might sound like a simple, throwaway term with not much of a story behind it, and that’s largely because it is. Scroop is just an echoism—an onomatopoeic word, first used in the early 1800s, and meant to do little more than imitate the soft characteristic crackling sound of silk. Before then, scroop was used more generally and has been recorded as far back as 1787 as a verb meaning simply ‘to make a scraping sound’.

What makes scroop more interesting than many other straightforward onomatopoeic words, however, is that it has been embraced wholeheartedly by the silk-making industry. And in fact considerable effort goes into both ensuring that high-quality silk always has its characteristic scroop, and, moreover, that cheaper silken fabrics—or fabrics meant merely to emulate silk—produce a similar feel and sound:

Dilute organic acids, tartaric and citric acids in particular, are used in the finishing of silk yarns and fabrics to produce a rustling effect known as “scroop”.

A Handbook of Fiber Chemistry (1998)

The crackling sound emitted when the fibre is squeezed and pressed is known as the scroop. The scroop does not appear to be an inherent property of the fibre itself. Silk can be scrooped by dipping it in dilute acetic or tartaric acid and then drying without rinsing.

A Text Book of Fibre Science and Technology (2000)