Take your kitchen scales to the shop when you're buying cashmere

Responsibly sourced cashmere is a sound buy: “Handwash it, or machine wash at 30°C, and it will last and last."
Mmm, cashmere. So soft and fluffy, right? As warm as toast, as light as bubble bath. What’s not to love?
A lot, actually. It turns out we are doing it wrong. Which is a bit of a shock, since cashmere has been one of the high street fashion success stories of our times.