What is paper made out of?

A bit of background first. Paper is a thin mat or pad of interlocking cellulose or similar fibers that have been pressed flat and smooth. The fibers are chosen for several characteristics such as strength, chemical stability, and an ability to hold ink or paint.The spaces in the mesh of fiber can be filled with clays to provide a smoother or heavier paper. Paper can be made of many materials: . The majority of paper seen every day is made of trees, specifically softwood trees that are cut, chipped and cooked in various chemicals to remove the binding chemicals (lignans) and release the cellulose fibers. These fibers are spread thin and essentially ironed flat into rolls of paper. Wasps do this same thing to make the paper for their nests, except that they chew the wood to separate the fibers. The finished product can be as soft as kleenx or as durable as Kraft paper, sometimes called butcher's paper. . Other plants such as cotton and linen can also provide fibers of suitable nature. These fibers are often used to make very high quality paper such as is used in paper currency. High quality paper often has content noted as containing so much "rag" this refers to the proportion of linen and cotton fiber in with the wood fiber. . Novelty papers are often made of unusual fibers. Many zoos produce paper from fiber recovered from sources like elephant dung. In these cases the fiber is actually cellulose from grass. Hemp shops often use hemp as the source of the fibers . Specialty paper can include plastic fibers for strength, clays for a better and smother surface, attractive plant materials like petals for colour and texture, and dyes for colour.