The important mission of envelope printing

Envelopes refer to thick paper jackets of letters or books. Their purpose is to insert a single page or sample into an envelope to form an integrated set of document materials. In China, envelope printing always plays an important role in the folder printing industry due to high quality and new technology.

The size of the envelope

The size of envelope printing is usually 6 or 4 open envelopes. Generally, the size of the envelope is slightly larger than the size of the insert. If there is more content to be inserted, a certain thickness needs to be left.

Envelope paper

Envelopes are usually made from thicker paper such as 200g, 250g or 300g. Paper type can choose copper plate / matte paper, cardboard or art paper. The general size is 220305mm.

Envelope printing

Offset printing usually uses offset printing. All need to be filmed and proofed before printing.

Post-processing of envelopes

The envelope needs to be coated or oiled after printing to protect the ink and increase its strength. After the printing is completed, the finished product is die-cut and bonded. Some jacket outlets can also be used as business card outlets, and you can also choose to have one or two outlets on the right side.

In recent years, many customers are no longer enthusiastic about the bookbinding of the entire album, and the "envelope and loose-leaf pages" publicity sample has gradually become popular. Generally 200 grams or more coated paper or white cardboard printing process, the cover back cover film, the inside side or double sided with a paper pocket. The paper pocket can hold a single color page, document or report of any combination of customers, and it can also hold some albums that are not too thick. The outer side of the paper pocket generally has a gap for inserting a business card, and the business card can be conveniently inserted therein. There are also some paper pockets for envelopes that are specifically designed to insert CDs in order to achieve "three-dimensional" publicity.

The type of envelope

The types of envelopes vary according to the material, such as hot melt adhesives, PVC envelopes, etc. A hot-melt envelope is a product used on a hot-melt binding machine and is a bound product that uses a resin material as a binding material. The book bindings that are usually read are simply glued together. The glue used is called hot melt glue. After the book is printed, the hot melt adhesive is applied to the book through the binding machine, and the binding is completed through wrapping and cutting. The hot-melt binding is to make a book cover first, and the hot-melt adhesive is preset at the book, which is called “hot-melt envelope”.

Post-printing process of envelope

The post-printing process of envelopes has a certain degree of particularity. According to the attributes of its products, it is divided into two parts: the necessary processing technology and the non-essential processing technology.

First, non-essential processing technology

This face-to-face process is mainly to increase the aesthetic section of the product. Common processing techniques include:

1, film. It is a processing technique that coats the plastic film with an adhesive and heats and presses the printed product to bond them together. After the printed product is coated, due to a layer of plastic film on the surface, it is smoother, and the degree of firmness of the gloss and color is also better. The graphic and text are bright in color and full of three-dimensional feeling. At the same time, it has waterproof, antifouling and abrasion resistance. Fold resistance and corrosion resistance.

2, glazing. A common technique in high-grade prints is to coat (or spray or print) a colorless, transparent coating on the surface of the print, thereby forming a thin, uniform, transparent and glossy layer on the surface of the print. Not only protects the printed matter, but also changes the texture and visual effects of the print.

3, from the drum. The process name is embossing and embossing, that is, a piece of intaglio plate with a tight fit and a letterpress, and the printed matter is sandwiched between the printed products. Under a certain pressure, a graphic or a pattern similar to that of the relief plate is formed on the surface of the printed product, so that the printed product has a distinct sense of relief. .

Second, the necessary processing technology

Because of the distinctive structure of the envelope, there is a paper pocket for loading documents (called "tongue" inside the printing industry), and the production of this part must go through "folding" and "paste". The process.

1, folding. By mechanical action, indentations that change the shape of the material are reserved on paper or other cut sheets for easy folding.

2, paste. The print is adhesively formed. According to the selected adhesive, the adhesive strength and the use environment limit will be divided according to the quality of general and high-grade paste, two situations.

It should be noted that, in general, these two processes need to be priced separately and cannot be ignored when calculating the cost of printed materials.