First.Advantage for Duplex board

Duplex board widely used for printing and package for toy, wine,shoe boxes ,tissue box ,gift boxes and tissue box etc .

Duplex board support for carton lamination and die-cutting .

Strong stiffness and folding resistance, good printing ink absorbency and further processed , with reliable and stable quality .

High surface intensity suitable for any kind famous brand of high-speed 4/6/8 colors offset printing.

Second.How To Measure The Gram Weight Of Gray Board Paper, And The Corresponding Relation With Thickness

What do we usually mean by 250 grams of grey board?Many customers may misinterpret it as referring to the weight of a sheet of grey board. In fact, the weight of a sheet of grey board refers to the weight of a sheet of paper per unit area.Overseas also has with each ream paper how many pound or how many kilograms are represented, can convert according to the length of paper, width and each ream sheet number into each square metre how many grams.Therefore, the paper by weight to calculate the price of sales.But domestic grey board, usually there is a deviation, so the goods on the market are rarely by weighing way to acceptance, which is based on the domestic．

Third.How To Distinguish The Quality Of Black Paper?

Black card paper is mainly C1S black card paper, C2S black card paper, black paper board with grey back, purp wood pulp black card paper, How to distinguish the quality of black card paper ?

1.Take C1S Black card paper for example, get the black card paper sample, first look  surface, fineness, whether there are white spots on the surface, another 45 degrees of Angle "black card paper" to look at the black card paper core, paper core is white, the impurity is not high quality black card paper.High quality "black card" core is black, commonly known as through heart black card paper, paper material is uniform, impurity is little, color wants even and brightness reflection is strong, the surface does not have excessive impurity, white dot and oil dot.And the surface is smooth and delicate, and should see "black card" whether the surface can see the trace that long fiber makes.

2. Folding test: if a piece of inferior "black card paper" is folded several times within 2500G, it is likely to burst the edge (burst line) or break. Otherwise, if a piece of high-quality "black card paper" is folded several times, the above situation will not appear.However, the resistance of black paper folding and product humidity is also related, such as paper too dry, black paper also easy to burst.

Above two points to distinguish black card paper quality is the most important two points, is due to the business to pay more and more attention to product package, and due to its particularity, black paper on the product packaging, is becoming more and more widely application, compared to other products made of black cardboard material also more high-grade, so for the master is important to distinguish the quality of the black card paper also.