Imagine you have a bag made out of a special kind of liquid called collodion. This liquid is like a very thin and sticky substance that can harden quickly when exposed to air.
To create a collodion bag, you would pour the collodion liquid onto a flat surface and let it spread out, then place a piece of clear plastic over it. Once the collodion dries, you can peel it off the plastic sheet and cut it into the shape of a bag.
The collodion bag is clear like a window, and you can see through it. But it's also resistant to water and air, so it can store things like wet photographic plates or other delicate instruments for transportation or protection.
Overall, a collodion bag is a clear and strong bag made of a special liquid that can be used to store delicate objects safely.