Our buying guide will enable you to understand what goes into choosing a custom size cardboard box. Paper, fluting and board grades are all simply explained to ensure you can use our instant calculator to choose the best box to meet your needs.
Decide which Grade of Board
Factors to consider when deciding which board grade you require include the weight of your product/contents, the storage conditions, how they will be transported once filled and suitability for printing and presentation. The information below can be used as a guideline in selection.
Traditionally cardboard boxes were constructed using a Kraft Paper (Virgin Material) as an outside liner, followed by test liner paper (Recycled) on the inside. The Kraft paper has longer fibres than the test paper giving the box more strength and the ability to withstand water ingress better and give it an overall better look.
Kraft paper is also much easier to print on, as the test paper with shorter fibres absorbs the ink from the surface.
As papers have increased in strength over the years, manufacturers have started using Test Liners as an outer liner as well as an inside liner which makes a slight difference in cost although the performance of the box is seldom as good.
Customers can also have both liners as a Kraft Paper along making the box stronger without increasing the flute. (Used if the product is damp or warm as the Kraft is far slower to break down.)
The corrugation between the liners is known as fluting. The various flutes available offer different properties over each other such as Compression, Crush or Burst strength, Printability or merely improved Transport or Storage space.
B Flute – Singlewall
Board calliper is approximately 3mm.
The most widely used flute profile due to its all-around compression strength, compactness, printability and cost-effectiveness. We make all styles of Boxes in this flute, and it is very suitable for the posting of lightweight product
C Flute – Singlewall
Board thickness approximately 4mm.
A larger flute than ‘B’ offering improved compression strength (Stackability), but is more easily crushed (Or Perforated), It takes up a little more space than “B” flute and is not as neat to Die-Cut
BC Flute – Doublewall
Board thickness approximately 6mm
This combination of ‘B’ and ‘C’ flute is commonly used where compression and stacking strength is required. BC grade is used where the weight of the product needs more stackability or when the box is travelling solo with a courier
Suggested Board Grade based on Content Weight
The strength of Board (Over against the physical construction discussed thus far) varies according to the weight of paper used. Typically expressed in Grams, per Square Mater, e.g. 125, 150, 200 or 300 as well as the mix of new and recycled wood fibre shown by a letter.
Kraft paper (‘K’) being of better quality (higher content of new wood fibre) than Test paper (‘T’)
As an example: 125 K/T B would mean the weight of the liner used is 125 grams per square metre, the external liner is Kraft and the internal Test quality with ‘B’ profile fluting
Single Wall Options
Grade Contents Weight
125 K/T (lightweight) 5 – 10 kg
200 K/T (heavy duty) 15 – 20 kg
Double Wall Options
Grade Contents Weight
125 K/T (lightweight) 10 – 15kg
200 K/T (heavy duty) 20 – 30kg
Many other factors enter into the final specification of a box, including but not limited to the proportions (Square boxes are stronger than rectangular), the contents (Static contents require less strength than dynamic), Weight distribution (Is the product evenly weighted) Shape of materials (Sharp edges or loose components)
We always recommend sampling before ordering a Production Quantity and are able to help you achieve and ideal specification
Now you have read our guide have a go at making the right box for you on our instant calculator