Sources and origins

Paper

Paper consists of fine fibres that usually come from wood, but hemp, flax, cotton or bamboo can also be used. Before wood from trees can be used to make paper it must be processed:

  1. the bark is removed using a rotating drum
  2. the remaining logs are chopped into small chips
  3. these are placed into a large steamer to break down the fibres and make wood pulp
  4. this passes through a screen that allows only pulp fibre of a certain size to pass through
  5. the pulp will then run through a series of rollers to compress it, achieving a consistent thickness and helping to bond the fibre together

The fibres are pressed together with water to make a pulp and then dried. Texture and surface finishes can be applied by adding chemicals, such as bleach, to the pulp. The paper can also be coated with an agent that fills the tiny spaces between the fibres, resulting in a smooth surface that has better colour absorption and sheen.

Production of pulp for papers and board is largely imported from China, USA, Japan, Germany, Canada and Finland, whilst rice paper is found in Eastern Asian countries, such as China and Vietnam.

Papers and boards are measured in grams per square metre (gsm). Paper usually weighs between 80-220 gsm; usually thicker paper suggests a higher quality.

Board

When paper or layers (ply) of papers weigh more than 220 gsm they are classified as boards. Board thickness is measured in microns (1/1,000 mm).

BoardPropertiesUses
Solid white boardStrong board made from bleached wood pulp, can be expensive, easy to print onPackaging, book covers
Corrugated boardTwo or more layers of a fluted (crimped) board sandwiched between board sheets, recyclable, impact resistantPackaging for products that need protection
Folding boxboardUsually consists of a bleached pulp top layer, unbleached, can be scored without splitting pulp middle layers and a bleached pulp inside layerCereal boxes, cartons, food packaging
A close-up view of rolled up corrugated card in green and brown.
Corrugated board

The main advantages of using papers and boards for commercial packaging include:

  • excellent print quality on most boards
  • excellent protection for products
  • relatively inexpensive to produce and process
  • can be easily recycled

A range of different papers and boards are available that have different uses:

MaterialDescriptionUses
Bond paperHigh-quality printer and writing paper, stronger and more expensive than copier paper but has a rougher appearanceWriting and printing
Heat transfer (sublimation) printing paperGood-quality colour images, expensive, not too absorbent, dye particles stay on top of the paper so they can be transferred at a later point usually with heatColoured printing with sublimation inks (dye suspended in a liquid for printing on to hard surfaces)
Foil-lined boardLaminated board consisting of a layer of foil (usually aluminium as it doesn’t react with food) and a layer of board, foil provides a good moisture barrier, strongFood packaging, take away containers
Packaging laminate, eg Tetra PakA laminate consisting of six layers (four polyethylene, with paper-based board and aluminium foil), maintains nutritional value and flavour of food, not recyclable in some areasFood and drink containers
Packaging laminate, eg paper-based boardStrong paper-type material, thicker than paper, smooth printing surfacePackaging, book and magazine covers, postcards
Packaging laminate, eg polyethyleneFlexible plastic layered with foil or other plastics, moisture barrier enabling paper-based board to stick to the foilFood packaging to prevent preservative gas escaping
Packaging laminate, eg aluminium foilProcessed from ore bauxite and used as an aluminium laminate, protects against oxygen and lightUsed in flexible packaging for food

Packaging such as Tetra Pak is made of six layers including board, polyethylene and foil. As a result, food products can be stored in room temperature conditions for up to a year. Containers such as this are designed to protect products stored inside against light, air and moisture.

The six layers that make up a tetra pack; metallocene polyethylene, low-density polyethylene, foil, low-density polyethylene, paper and low-density polyethylene.