Box containing Beltx stretch nylon Santy Panty

Box containing Beltx stretch nylon Santy Panty, "Secret-Keeper" with Sof-Thane stainproof shield, fits hip sizes 32-42, , with Walgreens discount sticker ($1.44), Beltx Corporation, St Louis, Missouri, 1973-1974

Before self-adhesive menstrual pads entered the market in the early 1970s, disposable pads had to be secured between the user’s legs with an elastic belt worn around the waist. As well as being uncomfortable, these garments were prone to slippage – and there was no mechanism to stop blood seeping through the pad once it was full.

By the 1960s, menstruators had another option: washable period underwear with a waterproof lining to provide additional protection against leaks. The Beltx Santy Panty had integral clasps at the front and back to hold a disposable pad in place.

Beltx Corporation went against the grain by opting to use a red colour scheme in their advertisements, yet the product’s tagline betrays a wider cultural discomfort with the idea of menstruation by assuring users of discretion: “Wear a Santy Panty like any brief … And your “secret’s” safe; what a relief!”

Fully reusable 'period pants' have undergone a resurgence in popularity since the mid-2010s, driven by consumers seeking a more comfortable and environmentally friendly alternative to disposable pads and tampons.