Paper milling is an industry that many people may overlook, but it plays a major role in everyday life. Books, cardboard boxes, receipts, tissues and printer paper all start their lives at a paper mill, where raw plant fibers are changed into finished sheets or packaging materials. 

Most modern mills depend primarily on wood as a source of fiber. The logs are peeled of bark and cut into small chips. The chips are then turned into pulp, a wet mash of cellulose fibers. There are two main ways to produce pulp. Mechanical pulping grinds the wood into fibers and retains most of the material . It is used for products such as newsprint . In chemical pulping, heat and chemicals are used to break down lignin, the natural glue that holds wood fibers together. This method yields a stronger and cleaner pulp, which is often used in writing paper and packaging. 

Once pulped , the material is washed and screened to remove dirt and undesirable particles . Depending on the product being made, Mills may also add dyes, fillers or coatings. There is often recycled paper added too. Used paper can be dissolved in water, cleaned of ink and recycled to make new products, reducing waste and saving resources. 

The pulp is then diluted with water and deposited on a moving screen. The water drains away and the fibers start to bond into one thin sheet. This sheet is run over rollers that squeeze out moisture and then through heated dryers that remove the rest of the water. 

Finally the paper is flattened, rolled or cut to size. Some of the types are coated to enhance the brightness or printing quality. Others become cartons or paper towels or pages of a notebook. 
Modern paper mills are also environmentally friendly. Many use recycled fiber, cleaner energy systems, and sustainable forestry practices to lessen their impact. 

Paper still matters, even in a digital world. The paper making process is used to make shipping boxes, food packaging, books, labels and hygiene products. This seemingly simple sheet is the product of elaborate engineering and mass production.