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

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Printed Paper Box Materials

For the custom paper box, the paper printed box is usually made of 4 kinds of paperboards. The SBS paperboard is white color inside and outside, which is widely used for the cosmetic paper boxes. The CUK, also referred to as SUS, is white color outside and kraft brown color inside, which is widely used for the beer carriers, beer cartons, beverage paper boxes. The kraft paperboard is kraft brown color inside and outside. It is used to make the kraft paper box and corrugated printed box. The CCNB paperboard is white color outside and grey color inside.

Paperboard Thickness and Grammage Conversion Table

单铜，双铜，白卡，白牛卡，牛卡，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 millimeters, while point is used in USA, which is abbreviated to pt. The formulas 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 = 0.254mm                                     11PT = 0.279mm  
12PT = 0.305mm                                     13PT = 0.330mm 
14 PT = 0.356mm                                    15PT = 0.381mm 
16 PT = 0.406mm=342gsm                    17PT = 0.432mm=350gsm
18 PT = 0.456mm=361gsm                  20 PT = 0.508mm=381gsm
20 PT = 0.508mm=381gsm                    21 PT = 0.533mm=400gsm
22 PT = 0.559mm=420gsm                   24 PT = 0.610mm=454gsm
26 PT = 0.660mm=488gsm                   27 PT = 0.686mm=513gsm
28 PT = 0.711mm=0.711gsm

paperboard-caliper-thickness-pt-conversion

Below is the paper details used at Shanghai 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 woodfree 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 paper boxes.
  • 5. The art paper is also called coated paper.

Conversion between gsm, pound, cover lb, text lb.

Text

Text is a classification of paper most commonly used for the interiors of books. Text stocks are usually measured in pounds (noted lb. or #). Text paper is widely used the booklet printing, manual printing, catalogue printing. It is usually 128gsm, or 157gsm art paper.

Cover

Cover is a thicker classification of paper most commonly used for book covers, measured in points (noted pt.) and sometimes in pounds (noted lb.). It is usually 157gsm or 200gsm art paper.

GSM

GSM (grams per square meter) is the metric system’s universal measure for paper weight and can be converted into lb. and pt. For example, 80 GSM is 55 lb. text and 350 GSM is 14pt. cover. Typically used to describe card paper.

https://okpaper.com/toolbox/calculators/calc-lbs-gsm

Formula:

1lb. of Text paper = 1.48 gsm. Multiply each pound of text paper by 1.48.

1 lb. of Cover paper = 2.708 gsm. Multiply each pound of cover paper by 2.708.

Solid Bleached Sulfate (SBS)

Bleached paperboard or solid bleached sulfate (SBS) is a premium paperboard grade that is white in color. In order to be considered SBS, the finished product contains no more than 20 percent recycled materials. The remaining 80 percent must be composed of freshly-harvested woodchips that are chemically processed and bleached. The bleaching process gives SBS its signature white color, both inside and out.

SBS is used to package everyday products, including food and beverages, cosmetics and pharmaceuticals. In order to print marketing and product information on the paperboard packaging’s surface, most SBS is coated with a naturally-occurring mineral called kaolin clay to improve its printing surface. If the packaging is intended for frozen foods or liquids, it may also be coated with a very thin plastic lining for wet strength protection.

Coated Unbleached Kraft Paperboard (CUK)

Similar to SBS, clay natural Kraft (CNK®) or solid unbleached sulfate (SUS®) paperboard (two variations of CUK) contains no more than 20 percent recycled material. However, when the 80 percent freshly-harvested woodchips are processed, they are not bleached and the paperboard’s bottom and inside layers remain the natural brown color.

Although the inner layers are brown, unbleached paperboard’s surface is still treated the same as bleached paperboard in order to create a printable and wet-resistant surface.

Shanghai DE Printed Box is a China medium-sized custom paper box manufacturer and packaging solution provider with facilities around 100,000 square meters in total. The company exclusively specializes in the supply and export of the custom paper boxes, including the paper printed box, corrugated printed box, cosmetic paper box, rigid paper box, cardboard gift box and custom paper bag. If you have any questions about the custom paper box, or would like us to give you a price quote, please do not hesitate to contact us by giving us an email.

上海DE印刷包装纸盒厂是一家业内领先的以出口为导向的高端包装纸盒生产商和包装解决方案提供商。公司拥有近10万平方米的厂房，仓库，研发和办公设施，专业生产印刷各种高端卡纸盒, 化装品盒， 瓦楞彩盒，瓦楞彩箱, 高端定制礼盒, 纸袋等印刷包装用品.