The glass has to be perfect glass. And, perfectly clear, washed very carefully with special wax. Then you have to pour the collodion (emulsion) on the plate. It evaporates very quickly because it has ether in it. You have to do it as fast as you can. Then you put the whole thing in pure silver nitrate & this is what makes it light sensitive. You take this wet, dripping plate & put it in a holder & then straight into the camera. You have no more than 2-3 minutes to take the picture and get back to the darkroom to develop it before it dries ......and it evaporates very quickly. Once the image is fixed & dry you pray it doesn’t peel. Then the best part of the process is the varnishing. It is made of amber resin and lavender oil and smells luscious. It is nice to keep it in a beautiful glass bottle. This liquid varnish gets poured on the plate. You heat the plate over a candle until the varnish dries. You are now living back in the mid 1800's.