Commercial menstrual products began to be developed and sold in the United States in the late nineteenth and early twentieth centuries, but the early commercial options were limited, often uncomfortable, and prone to specific mechanical failures that women who used them found frustrating.

Mary Kenner began thinking about this problem while she was still young — some accounts suggest she was thinking about improvements to menstrual product design as a teenager.

Her specific insight was about the mechanical design of the attachment system: the way that the sanitary napkin connected to the belt that held it in place.

The existing designs were unreliable and uncomfortable in specific ways, and she thought she could do better.

Her design for an improved sanitary belt included a moisture-proof napkin holder built into the belt itself.