Do you find lighter patches in your dark underwear? IT'S NORMAL! Your vagina is acidic and has a pH of 3.8-4.5. That's acidic enough to bleach fabric, and that's what's happening.

These knickers appear in our #Muffbusters exhibition, and we get a lot of feedback from people who didn't know that it happens, or why it happens or fel relieved to learn it wasn't just them. So let us tell you this: it's normal.

We've also been asked a few times how we "made" the bleached knickers for our exhibition - we didn't. They're real pairs of pants from real people.

The light patches in underwear isn't staining from period blood or discharge, it's bleaching - the same as if you've ever tried putting lemon juice in your hair to lighten it.

It's not a sign of dirtiness or bad hygiene to have paler patches in your pants, it's something which happens when the acidity of a perfectly healthy vagina spends time in contact with fabric, and it's particularly noticeable on darker fabrics.

So, it's not just you. Lighter patches in your knickers are normal, and there's nothing to be ashamed of!