Products that women invented for domestic use were sometimes dismissively categorized as “gadgets,” a word that implied something cute and minor rather than something genuinely useful and commercially significant.

Mary Kenner’s inventions were almost entirely in the domestic and personal care sphere — precisely the sphere that was gendered as female and therefore treated as less commercially serious.

Her sanitary belt invention addressed a specifically female biological need.

Her back washer and walker attachment addressed needs associated with home care.

Her ashtray and bathroom tissue holder were domestic products.

This means that her inventions were both exactly in the space where her knowledge was deepest and most direct — she invented from personal experience — and exactly in the space where the male business establishment was least likely to take her work seriously.

The double bind of being a Black woman inventor is visible here: she was inventing in the areas where her knowledge was greatest, and those were precisely the areas where race and gender bias were most likely to operate against her.