Sit for a portrait the way it was done in the 1860s: on a sheet of black iron, coated and developed by hand while it is still wet.
The picture never leaves this page.
How a tintype works
A tintype is made directly on a thin sheet of iron, lacquered black. The plate is coated with collodion, guncotton dissolved in ether and alcohol and salted with iodide, then dipped in silver nitrate, which turns the film creamy and sensitive to light. It has to be exposed and developed while it is still wet, inside about fifteen minutes.
Collodion sees only blue and ultraviolet light. Blue eyes come out pale, red lips and freckles dark, and a blue sky white. Your camera's colours are weighed the same way here.
The developer brings up a thin silver negative. Once the fixer has dissolved the unused cream, the silver reads as a positive against the black iron. There is no negative to print from, so every plate is the only copy, and it is a mirror image: you see yourself as you would in a glass.
Studio exposures in daylight took a few seconds, and sitters were braced to keep still. Anything that moves while the lens is open leaves a ghost.