Papers commonly used in publishing and printing（4）

Whiteboard paper is a kind of cardboard with white and smooth front side and gray bottom on the back. This kind of cardboard is mainly used for single-sided color printing and made into cartons for packaging, or for design and handmade products.

Important materials for book box binding include white cardboard, yellow cardboard box cardboard, etc., which are mainly used to make hardcover book covers and envelopes. The hardcover book case with cardboard as the skeleton has the advantages of firmness, beauty, and long-term preservation.

Calcium plastic paper is a kind of beautiful, non-toxic, tasteless, light and moisture-proof, high compressive strength, corrosion resistance, and good hand feeling with high-density polyolefin as the main raw material. The length of the product is unlimited, and it can be painted in various colors. It is widely used in pesticide, machinery, chemical, food and other industries and internal and external packaging. It is currently the most ideal packaging material for replacing wood with plastic and paper.

Kraft paper is a tough, water-resistant packaging paper with a brownish-yellow color and has a wide range of uses. It is often used to make paper bags, envelopes, record sleeves, files and sandpaper. The basis weight range is from 40 g/m² to 120 g/m². There are differences between web and flat paper, single-sided light, double-sided light, and stripe. The main quality requirements are flexibility and strength, high burst resistance, and ability to withstand greater tension and pressure without breaking.

Cellophane is a kind of film made from natural fibers such as cotton pulp and wood pulp and glued. It is transparent, non-toxic and tasteless. Because air, oil, bacteria and water are not easy to penetrate cellophane, it can be used as food packaging. It is also known as transparent paper, which is a high-grade packaging and decorative paper that is as transparent as glass. It is used to wrap food, food, shirts, cigarettes, cosmetics and other commodities. The basis weight is 30 g/m². In addition to being transparent and colorless, there are many colors such as golden, pink, emerald and so on. Cellophane is airtight, oil and water, soft, strong, colorless, transparent, and shiny. After sealing, it can be moisture-proof and rust-proof, but it will crack if there is a slight crack. Because of its high longitudinal strength, it can be made into paper rope. Waste cellophane cannot be recycled.

Mailing paper is a kind of extremely thin single-sided glossy writing paper, with a basis weight of only 20 g/m2. It was originally mainly used for sealing paper for postage stamps and insured letters. Now it is mostly used in cosmetics, fruit and food packaging and cigarette lining. After printing and waxing, it can be used as candy wrapping paper, or it can replace typing paper and copy paper to print receipts, subpoenas or multi-page carbon paper. The quality requirements are thin and strong, with good transparency, high tension and low air permeability.