Monthly Archives: March 2014

Paper Grammage(GSM), PT and Thickness Comparison and Conversion Table

Paperboard Thickness and Grammage Conversion Table

单铜,双铜,白卡,灰底白板纸张克重gsm, 厚度和pt对照转换表格

In China, the thickness of the paperboard is measured in milimeters, while point is used in USA, which is abbreviated to pt. The fomulas below can be used for the conversion of the 2 units.

1 inch =25.4mm = 1000 pt. 

1 pt = 0.0254mm

For example, 60pt=60*0.0254mm=1.524mm. The 60pt chipboard in USA refers to the 1.5mm greyboard in China, which is very ideal for the small rigid paper boxes. When you need a strong rigid box, 80pt chipboard can be used, which is 2mm thick greyboard in China.

– 标准厚度(mm)         – 标准厚度(mm)  
10PT 0.254                    11PT 0.279  
12PT 0.305                    13PT 0.330  
14 PT 0.356                   15PT 0.381  
16 PT 0.406                   17PT 0.432  
18 PT 0.456                   20 PT 0.508  

Below is the paper details used at DE Printed Box.

白卡纸,单铜(SBS C1S) 双铜纸(SBS C2S) 哑粉纸,铜版纸(Art Paper) 双胶纸(Woodfree Paper)
GSM mm GSM mm GSM mm GSM mm
210 0.27 80 0.06 105 0.09-0.1 80 0.095
230 0.3-0.31 105 0.08 128 0.12-0.13 100 0.11
250 0.33 128 0.1 157 0.16 120 0.14
300 0.4-0.41 157 0.12 200 0.19-0.2 150 0.17
350 0.47-0.48 200 0.17 250 0.25 180 0.2
400 0.55 210 0.21 300 0.31 200 0.23
230 0.25 250 0.29
250 0.265 300 0.33
300 0.35 350 0.4
350 0.41 400 0.47
400 0.465
SBS C1S(白卡)PT/GSM Comparison Table SBS C2S(双铜)PT/GSM Comparison Table
PT 标准克重GSM 使用克重 PT 标准克重GSM 使用克重
7PT 161g 7PT 182g
8PT 174g 190g 8PT 195g
10PT 199g 210g 9PT 225g 230g
11PT 225g 230g 10PT 234g 230g
12PT 236g 250g 12PT 272g 300g
14PT 265g 300g 14PT 306g 300g
15PT 280g 300g 16PT 340g 350g
16PT 296g 300g 18PT 358g 350g
18PT 324g 350g 20PT 420g 400g
20PT 345g 350g 24PT 230G白卡对裱
22PT 379g 400g 30PT 300G白卡对裱
24PT 407g 400g
26PT 435g 450g
灰底白板(Duplex Board with Grey Back) 白底白板(Duplex Board with White Back)
GSM mm GSM mm
250 0.32 300 0.37-0.38
300 0.37 350 0.44-0.45
350 0.44-0.45 400 0.5-0.51
400 0.49 450 0.57-0.58

Note: 1. The duplex board with grey back is also referred to as the while lined chipboard with greyback, clay coated new back(CCNB).

2. The duplex board with white back is also referred to as the white lined chipboard with white back.

3. The wouldfree paper is also referred to as the offset paper

4. The SBS C1S, C2S is also referred to ivory board or art paper in China. C1S means that the paper is coated on only one side of the paperboard. C2S means that both sides of the paperboard are coated. Ivory paperboard in China usually refers to the SBS C1S. Such papers are used to make the luxury printed paper boxes and cosmetic boxes.

5. The art paper is also called coated paper.


Why is Bleed so Important?

Before we discuss the importance and necessity of bleed, let’s first expain what bleed is.

1. What is bleed in printing?

Below is a paiting to be printed. The blue line refers to the cut line. Everything outside the blue line will be trimmed. The bleed line is 3mm away from the cut line on the outside. While the green line is the safe line. Every essential elements of the painting needs be inside the safety zone, in case they are trimmed during the die-cutting.


2. Why is bleed necessary during the pre-printing design?

The inaccurate die-cutting is the root cause of the bleed zone setup. The die-cutting is accurate generally, but not 100% in theory. Without the setup of the bleed zone, a thin white area on the edge may appear on the finished piece.

Now we understand the essence of the bleed. Therefore, when we create an artwork ready for printing, the background image must be extended 3mm(0.125″)away beyond the cutline.If a brochure has the final size 210*297mm, then the artwork should at least has the size 216*303mm.

3. Safety Zone

The safe line is usually 6mm(0.25″) away from the cutline. It is inside the cutline. When the texts go over the safe line, they are risk being cut off during the trimming process.


Creating a Dieline

What is a dieline?

A dieline is a 2-dimensional graphic design of the outline of a packaging box, which shows the box cut line and the fold line. Usually the cut line is represented by the solid line and the fold line by the dotted line in another color.

How to create the dieline?

Adobe Illustrator is widely used in the creating of the box dieline. However, AutoCAD seems much more powerful when the box has a complex design and structure. AutoCAD makes the design more accurate and easy when the complicated flip, rotate, and mirror are involved. Personally, I prefer AutoCAD when I need create a dieline.