There are three dimensions that define the size of a corrugated boxes; length, width and depth (height). The width is always defined as the shorter of the two sides. When determining the size of corrugated boxes the measurements are taken from the inside of the box to make sure the item will fit.
Two things determine the strength of a corrugated box, the material that is used and the number of layers of cardboard. A corrugated box consists of two components – liner and medium. The liners are made up of linerboard the flat sheets that are seen on both the inside and outside of a cardboard box. The medium is made up of fluted paper, - the wavy center - that is sandwiched between the two sheets of liner. The flute when glued to the liner becomes very durable and support tremendous amounts of weight.
The medium and linerboard can be combined in a number of combinations depending on the needs of the customer and the purpose of the box.
- Single-Face: One medium is glued to a single piece of linerboard.
- Single-Wall: The medium is between two sheets of linerboard.
- Double-Wall: Two mediums between three sheets of linerboard.
Once the style of box has been determined, the corrugated fiberboard is cut, slotted and scored. This is called a box blank. For many types of boxes it is necessary to attach the two ends together. Where the two ends of the box blank are joined is referred to as a joint. This can be done using glue, tape or staples (stitched join).
Linerboard generally comes in Kraft (brown). However, it can also come in Oyster (white) in most flute and linerboard strengths. Though it may need to be specifically ordered.
Kraft linerboard and medium will usually suffice for most jobs. Oyster is primarily used with Pharmaceutical, Dental and Food products.