Printing Paper Types
The resin coated paper types have a plastic coating on them, like the photos you would receive from a photolab. This stops the chemicals from penetrating into the paper, meaning that the chemical and water usage is fairly low. The prints only require about 5 minutes of washing, although slightly longer is given to ensure that there are no problems.
Fibre Based paper has no coating sealing the paper base. This means that the chemicals soak into the paper more readily, using more chemicals in the process. It also means that it takes a lot longer to ensure that the paper is free of the chemicals, typically 1 hour plus of wash time.
Although there are differences, once behind a sheet of glass, it is very difficult to tell.