The Safety Razor came about through a series of inventions that led to the current form. The modern double edged safety razor form was patented by King Camp Gillette in 1904.

Before cheap disposable stamped blades, razors were maintained by stropping and honing, so Gillette made the lack of stropping a selling point, as in this 1905 ad.

Gillette ad

1904 patent by King Camp Gillette.

Safety razor patent