Carbonless paper is generally two, divided into the upper and lower paper. The front of the upper paper in contact with the front of the paper and the front of the lower paper can be copied, two sheets of upper paper or two sheets of lower paper is not able to produce the effect of rewriting, because the reverse side of the upper paper, the front and back of the middle paper, the front of the lower paper are available to rewrite the chemical molecules endowed on its surface. Carbonless copy paper is used in documents, existing invoices, contracts, treaties and other legal effects of formal documents have all used carbonless copy paper. Such as: postal (sealing postal lists, delivery of postal waybill) bank (bank settlement vouchers, bank POS single), medical (medical receipts, fee receipts, prescription lists, drug sales lists, drug inventory list), hotel (hotel checkout), energy (water, electricity and coal bill, utility bills, gas security checklist), concrete (electronic weighbridge, delivery note), textile, chemical fiber (chemical fiber packing list, Textile, chemical fiber (textile printing and dyeing processing orders, product labels, material acceptance form), logistics (logistics freight bill), electronics and electrical appliances (product warranty card), hardware (hardware processing orders), jewelry (jewelry quality assurance sheet) and other industries with holes in the form of printing.
Duplex paper usually refers to printing paper, also called offset paper. It was previously known as Dowling/Dowlin paper. It possesses the characteristics of small stretchability, good flatness and smoothness, and strong water resistance. Typically, the basis weight of the double offset paper is between 60-120g, but there are also high weight double offset papers above 150g. In this the most widely used double offset paper for 70-120g. less than 60g is not double offset paper and called writing paper, paper type is relatively poor.
The main use of double-gummed paper is relatively broad, mainly for the production of various types of books. It can also be used for magazines, journals, promotional pages, catalogs, maps, calendars, calendars, covers, inserts, illustrations, product brochures, manuals, anime and manga, cute cartoon books, advertising posters, corporate brochures, advertising flyers, envelopes, books, notebooks, and its dye embossing, forms, corporate office/correspondence paper, business cards, colorful trademarks, and a wide range of packaging supplies, and so on.