Wet plate photography is a nearly extinct method that was developed in the late 1800s. The process uses glass or metal plates to capture the image. It requires a chemical bonding agent called collodion and silver nitrate, which is what makes the plate light sensitive. While wet the plate is placed in the camera for exposure. The plate is then developed and fixed like film; the plate becomes your negative to make prints off of.
Ian Ruhter is a modern day photographer who has devoted his life to traveling around and utilizing wet plate photography. He turned a van into one large camera so he can produce large-scale images on the road. It is a complicated and difficult process but when it works its extremely rewarding.
Here’s a link to a video explaining who Ian Ruhter is and what he does.