...but can you really give them a machine-wash?

POPulArISeD by the likes of Kate Beckinsale, Amanda Holden and model Gigi Hadid, the trend for silk pyjamas is booming. But washing them is fraught with risk.

The fibres are prone to snagging and the colours can run, so it’s no surprise silk brands tell us to dry-clean only or hand-wash. until now, that is. Suddenly the High Street is awash with sophisticated sets that promise they can be washed in the machine, tumble-dried and even — gasp! — ironed.

In fact, according to fabric technologist Mairwen Jones, the reason we’re advised to dry-clean rather than machine-wash some silks is not always down to the fabric itself, which is a natural protein fibre usually produced by silkworms to build their cocoons.

‘It’s more often about protecting the brand,’ she explains. ‘A dry-clean label protects against a company having to accept and replace returns if the fabric shrinks or the colour runs when a garment is washed at home.

‘Many brands don’t have the systems in place to deal with that. Mass-market retailers such as H&M do lots of fabric tests, such as colour-fastness for machine-washing, as they buy such large quantities — for others it is simply not economical, or viable.’

Still, surely some silks wash better than others? Maybe slightly, says Mairwen, but that’s mostly dependent on thickness — thicker washes better — and whether they have embellishments or sensitive trimmings rather than anything else. Most silk, if treated gently and washed at 30 degrees or less, with the correct non-biological detergent, will manage OK being carefully washed on its own.

It helps, too, that recent fabric processing advances mean dyes last better and fibres are more tightly woven and less prone to shrinkage. ultimately, retailers are becoming more confident their silk will withstand your wash cycle.

Here, Femail puts three machine-washable silk pyjama sets to the test, following their washing and drying instructions to the letter.

So how did they fare in terms of shrinkage, fading, wrinkles and wear and tear?