Pulling almost always comes down to three things, in this order: how wet the hair was, how slick the lather still is, and whether the edge is finished. Most people check them backwards.

Razor companies have to write down what is wrong with their own razors. It is the price of a patent. We read fifty years of it — and the strangest thing in the pile is a razor from 2003 that was going to tell you to stop pressing.

American sorting lines are built to miss objects under two inches across. So a razor in the recycling bin is landfilled as residue, at the plant's expense. In the trash it has roughly a one-in-five chance of its steel coming back.

Dermatology says far less about shaving with acne than the tip lists do. What it does say is short, and most of it is about a different problem that looks exactly like acne.

About thirty degrees — but that number is close to useless on its own, because you can't see the blade. What you can see is which parts of the razor head are touching your face.

No double edge blade is built for sensitive skin, and the lists that name one are ranking brands, not properties. What decides whether a shave feels harsh is mostly the razor holding the blade.

A Gillette blade cost about $2.99 in 1909, in today's money. A Gillette cartridge costs $4.99 now. The consumable barely moved — the hardware fell from roughly $179 to three dollars. Here is what the archive, the index and one shelf actually say.

Most sensitive-skin advice tells you what to add. Adding five things at once tells you nothing. The faster route is subtraction: take one thing out of the shave, wait two weeks, watch what changes. Here is the order to take them out in, and why that order.