There are basically two types of photographic paper fiber-based and resin-coated. Whichever is used, the surface is coated with a light-sensitive emulsion that carries the image.this
Resin-coated (rc) paper has a thin coating of plastic, so the emulsion doesnt penetrate into it, but sits on top as a thin layer, preventing the damaging processing chemicals from penetrating into the paper itself. The material is still too new to know how long a print made on it will last, although indications are favorable.
Fiber paper is made of a natural fibrous material (cellulose), so the light-sensitive emulsion sinks into it. Although this makes processing more difficult, it could add a depth and warmth to the tones of the image. Processed properly, it appears to be archival (its been around since the mid 1800s.)
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