The primary use of Cosmos blotting is simple: wet blotters are used to dampen the art paper in preparation for printing - the paper can be sandwiched between the damp/wet blotters and are usually left overnight so the paper can take on enough moisture.
In reverse when a print is pulled and it is still quite damp the drying time can be greatly reduced if it is placed between 2 dry blotters that act as a sponge taking on the excess moisture from the final print.
Because of its total lack of any sizing (internal and external), Cosmos Blotting has been used successfully for paper-casting or molding shapes and sculpture pieces. It also makes for a great option for custom coasters.