Thickness and material are the two main factors that determine the hardness of a carton. There are usually three or five layers of cartons. Of course, there are still seven thicker layers. The more layers of cartons, the stronger they are. The three layers are not the flat plate with three layers, but two layers of flat plates with a layer of corrugated in the middle.

五層則為三層平板加雙瓦楞;三層、五層紙箱又名單瓦楞和雙瓦楞紙箱;紙箱材質也有多種，好的材質不光硬度高，而且分量輕，差一些的材質往往硬度很，很簡易變形;市情上紙箱的材質從高到依序是“KK>KA>KB>AA>AB>BB", KK材質是目前對照好的材質。

Five layer is three-layer flat plate with double corrugated; three-layer and five-layer cartons are also listed as corrugated and double corrugated boxes; there are many kinds of carton materials, good materials not only have high hardness, but also light weight, and poor materials often have low hardness and easy deformation; in the market situation, the order of carton materials from high to low is "KK > Ka > KB > AA > AB > BB", and KK material is the current good material.

三層的厚度就充足承載一個正常成人年的分量，表面平滑有質感，KK好是好，可是售價也是對照貴的，AA，BB材質雖硬度稍弱，可是搭配五層的厚度，也有很高的硬度，足以保護好產物不受破損。

The thickness of three layers is enough to carry the weight of a normal adult year. The surface is smooth and has texture. KK is good, but the price is also relatively expensive. Although the hardness of AA and BB materials is slightly weak, but the thickness of five layers also has high hardness, which is enough to protect the products from damage.

我提議賣家根據(jù)自身的需求，選擇差異類別的紙箱，譬如易碎、珍貴物品不妨運用五層AA紙箱，尋常經摔的物品，或許商品自身自帶紙盒的，選擇三層的就充足了。

I suggest that sellers should choose different types of cartons according to their own needs. For example, fragile and precious items, they may as well use five layers of AA cartons. For ordinary items that have been dropped, or if the goods have their own cartons, they should choose three layers.