Board Grades
There are 4 elements involved in the description of corrugated board - the weight of the board, the flute, the type of the board and the combination of the layers in the board:
| Weight | This is a number representing the grams per sq metre of the board. For example the most popular weights are 125, 150 and 300. The weight used in an application is determined by what goes in the carton and how it is to be transported. As a rough rule of thumb specify 125 or 150 for lighter weights and use a 300 only for double wall applications. |
| Flute | A letter from "A" to "E" is used to describe the flute - that is the corrugated layer in the middle of the sandwich. Most lighter applications use "B" flute, moving up to "C" flute for heavier items and a "double wall" for the heaviest items, usually a combination of "B" and "C". |
| Type of board | This describes the type of paper used in the inner and outer layer. The standard is for the outer layer to be made of a stronger, virgin paper called Kraft ("K") and an inner layer using recycled fibres called Test ("T"). Where appearance is important you could use White or OysterBoard (mottled white). Whilst each board can be different weights they are normally the same. |
What do they look like and how are they described ?
| Single wall |
This has a single fluting, hence single wall, and is decribed as top layer weight ,oblique ("/"), bottom layer weight+flute e.g. 125K/125T B flute |
| Double wall |
This has 2 flutings, and an additional mid layer. It is described as top layer weight +1st flute + 2nd flute + bottom layer weight, e.g. 150K BC 150T Flute |
