Watermark paper in the manufacturing process, watermark paper can be made into paper by using the marks and patterns required by technical means. These patterns are not easy to see under normal circumstances and can be seen only against the light. Banknotes, important documents, facility drawings and various tickets in most countries are also printed with watermark paper. It integrates design, mold carving and network making in manufacturing, In complex technological processes such as paper making, checking watermark is also one of the effective means to identify true and false.

包装印刷有叠影便是用一块印刷版印出来的图象错移，在印数上可以见到双向、三重的图影。有叠影的缘故有多种多样，例如打印纸张，叼牙、滚桶、丝印油墨、印速、印刷油墨黏度等多种要素比较复杂，一般能够选用下列好多个方式来查验缘故并。防复制印刷纸这种纸张复印后，会浮现“复制”和“无效”的字样，可有效防止彩色复印重要文件，另一种全吸收型防复印纸外观呈蓝色或棕红色，纸上图文只有透过光才能看到，其复印件一片漆黑。

There is overlap in packaging printing, that is, the image printed with a printing plate is shifted wrongly, and two-way and triple image shadow can be seen in the number of prints. There are many reasons for overlapping, such as printing paper, teeth, barrel, silk screen printing ink, printing speed, printing ink viscosity and other factors are complex. Generally, the following methods can be used to check the reasons and solve them. Anti copy printing paper after copying, the words "copy" and "invalid" will appear, which can effectively prevent color copying of important documents. The appearance of another full absorption anti copy paper is blue or brownish red. The pictures and texts on the paper can be seen only through light, and the copies are dark.

封套纸张通常选用250g或300g等较厚的纸张。纸张类型可选择铜版/哑粉纸，卡纸或艺术纸等纸张类型可选择铜版/哑粉纸，卡纸或艺术纸等。

The envelope paper is usually 250g or 300g thick paper. The paper type can be coated / matte paper, cardboard or art paper. The paper type can be coated / matte paper, cardboard or art paper.

1、纸张说明：铜版纸是常用的封套用纸，手感厚实，给人一种稳重感，适合各类商务使用。

1. Paper Description: coated paper is a commonly used envelope paper. It feels thick and gives people a sense of stability. It is suitable for all kinds of business.

2、纸张克重：250克、300克、350克、400克。

2. Weight of paper: 250g, 300g, 350g, 400g.

3、优点：进口铜版纸，防汗防潮，不易粘灰尘，色彩还原度更好，适合各种颜色。

3. Advantages: imported coated paper, sweat proof and moisture-proof, not easy to stick to dust, better color reduction, suitable for all kinds of colors.

4、缺点：几乎没有什么缺点。

4. Disadvantages: there are few disadvantages.

5、设计要求：颜色丰富或有大面积色块的封套设计图。

5. Design requirements: envelope design drawings with rich colors or large color blocks.