File photo: Fabrics such as cotton can be abrasive, dehydrating the skin.

Bedtime has a familiar routine for 50-year-old Luigia Minichiello. Whether she’s in a far-flung hotel or tucking up at home, she sleeps on a pure silk pillowcase.

While it sounds the ultimate luxury, the preserve of Hollywood divas or aristocracy, women such as London-based events manager Luigia swear they’re an essential anti-ageing device, as effective as any expensive treatments.

She says silk pillowcases keep her skin unlined, hair soft and improve her sleep quality.

No wonder high-end bedding company Soak&Sleep is saying it’s noticed an 11 percent rise in sales year on year.

"When travelling, every night I’d unfold my pillowcase and know I was staving off the effects of ageing," says Luigia.

Silk has been prized for centuries — it’s said silk farming dates back more than 7 000 years. The silkworm eats mulberry leaves, spins its cocoon and produces silk thread.

"There are many reasons for silk’s beauty benefits," says physiotherapist and sleep expert Sammy Margo, author of The Good Sleep Guide.

"Most of us sleep on our sides, with our faces pushed into the pillow, often waking with creases or indents in the skin. These take longer to disappear as we age and collagen and elastin are less effective."

This is because fabrics such as cotton can be abrasive, dehydrating the skin.

"Silk’s smooth surface means you won’t wake up with a face like scrumpled up paper," says Sammy. "Your moisturiser can also do its job better — it will be absorbed rather than dragged all over the pillow."

The antioxidants in silk may also counter effects of ageing. Tests show mulberries contain up to 79 percent more antioxidants — which aid cellular repair — than superfruits such as blueberries.

"It’s possible skin moisture and heat may release antioxidants in the fabric," says aesthetic expert Dr Hilary Allan at Woodford Medical.

Some silk pillowcase makers refer to research which says sericin, a protein in silk, can adhere to keratin, a protein in skin and hair, resulting in a barrier layer that helps retain moisture and may have a plumping, anti-ageing effect.

Luigia still won’t leave home without her pillowcase. "When I visit friends, I take it with me. It’s a running joke, but the joke will be on them in a decade’s time!"