Applications of Papers and Boards: Performance Characteristics

Objectives

  • Be able to name a range of papers and boards and describe their performance characteristics
  • Understand how some papers and boards can be designed to be impact resistant
  • Evaluate the properties and applications for a range of different paper and board products

Starter

  • What’s the difference between paper and board?

Two-Minute Challenge: Weight Order

  • Place the following papers & boards in the correct order by their weight (GSM):
    • Cartridge paper
    • Mountboard
    • Tracing paper
    • Tissue paper
    • Photocopy paper
    • Layout paper
    • Foil-lined board
    • Bleed proof paper

Winner Reveal: GSM Ranges

  • There is no definitive order as the GSM ranges overlap; actual samples are needed for precise comparison.
    • Tissue paper: 10 - 35gsm
    • Layout paper: 40 - 60gsm
    • Tracing paper: 40 - 120gsm
    • Bleed proof paper: 70gsm
    • Photocopy paper: 70 - 150gsm
    • Cartridge paper: 120 - 150gsm
    • Foil-lined board: 200 - 400gsm
    • Mountboard: 500 - 2500gsm

GSM vs. Microns

  • Paper is classified by both weight and size.
  • Paper weight is measured in grams per square metre (GSM).
  • Paper-based materials that weigh more than 220gsm are usually classified as boards.
  • Board is usually measured in microns (μ\mum); 1000μ\mum is 1mm of thickness.
  • Paper sizes are set globally using the A, B, and C series.

Paper Sizes: A, B, C Series

  • ISO 216 governs paper sizes internationally.
  • A series: Standard trimmed paper stock.
  • B series: Alternative sizes often used in industry.
  • C series: Used for envelopes.
  • Commercial untrimmed sizes:
    • RA series: 105% of A series.
    • SRA series: 115% of A series.
  • Untrimmed sizes are needed to allow for bleed and trimming during printing.

Card vs. Board

  • Paper over 220gsm tends to be called card, but the distinction from board is not always clear-cut.
  • Cards and boards are available in a range of thicknesses and strengths.
  • Card is usually measured in GSM, but board more often in microns.
  • Board can be made from recycled paper unless it is of food grade.
  • Boards can be laminated to other materials or layered to enhance strength, surface finish, or durability.

Corrugated Card

  • Made up of one or two flat outer layers (liners) and a corrugated medium (fluting).
  • Flexible in single-layer form; directionally rigid with a good strength-to-weight ratio.
  • Shock-absorbing, lightweight, and good thermal insulation make it perfect for packaging.
  • Stronger in one direction due to the orientation of the corrugated medium.

Corrugated Card: Weight Ranges

  • Different corrugated boards include:
    • Single wall: 3000 - 5000μ\mum
    • Double wall: 6000 - 10000μ\mum
    • Triple wall: 12000 - 15000μ\mum
  • Applications are determined by the required strength and protection.

Corrugated Card: Pros and Cons

  • Advantages:
    • Easy to handle during packing and loading.
    • The outer layer can be printed on for branding and advertising.
    • Readily available in a range of sizes.
    • Cheap due to lower grade raw materials and a natural finish.
    • Fully recyclable.
  • Disadvantages:
    • Readily absorbs moisture.
    • Cannot pack very heavy items as it can tear or collapse when stacked.
  • Laminates or coatings might prevent it from being easily recycled.

Tracing Paper

  • Semi-transparent, grey in colour.
  • Good for tracing ideas and overlaying or transferring one image to another.
  • Relatively hard and strong.
  • Usually around 40-120gsm.
  • Acid is used to treat the paper, giving it its transparency and making it resistant to grease.

Layout Paper

  • Slightly transparent but greater opacity than tracing paper.
  • Off-white colour, around 50gsm.
  • Not as strong as tracing paper.
  • Good for tracing ideas and laying out plans.
  • Often used in a sketch pad or large sheet format.
  • Takes pencil well.

Bleed Proof Paper

  • Designers use bleed-proof paper for hand-drawn marker renderings.
  • It does not allow ink or solvent-based marker pens to bleed through.
  • Highly sized with high opacity, giving deeper colours.
  • Normally 70gsm.

Cartridge Paper

  • It has a creamy off-white colour, primarily used for sketching.
  • The surface qualities take various drawing media very well.
  • Used in Art and D&T departments for use with pens, pencils, pastels, crayons, inks, and some paints.
  • Slightly textured finish.
  • More expensive than copier paper due to its higher quality and suitability for art applications.

Watercolour Paper

  • Artists use this for painting in watercolours.
  • Highly absorbent – therefore little or no sizing.
  • It can withstand large amounts of water and retain its structural integrity, remaining flat when dried.
  • It has a matte, lightly textured finish.

Photo Paper

  • Three main types of photo-quality paper:
    • Inkjet paper: Has a non-porous treated surface so the image stays sharp.
    • Laser paper: Has surface coatings designed to permit the plastic particles in toner to melt and bond onto the surface of the paper.
    • Photographic paper: Which has a photosensitive coating, reacts to light, and the image develops over a short time.

Mount Board

  • Used for mounting photos and pictures before framing.
  • It’s structurally very strong.
  • Available in a wide range of colours.
  • It normally has a white core which shows when it is cut at a 45° angle when used as a mount for framing.
  • Good for making final models but too expensive for prototypes.

Bleached Card

  • Bleached white card, also called solid white board, is highly brightened and treated on both sides.
  • It is used for a range of products including high-end packaging and greeting cards.
  • It holds print very well and has a luxurious feel to the surface.
  • Usually available between 200 to 500gsm.

Duplex Board

  • This twin-layered board is usually used for packaging.
  • The top layer is normally white but available in a range of colours.
  • It is food safe and can be coated to increase water and oil resistance.
  • It folds, cuts, and prints well.
  • Usually around 200-500gsm.

Foil Backed and Laminated Card

  • Some boards are coated or laminated with other materials to enhance their working properties.
  • Foil linings create an impermeable layer protecting the contents from light, air, odour and bacteria.
  • Polyethylene is used as a food-safe liner, an adhesive between the card and foil layers, and as an outer coating.

Tetra-Pak® Deconstructed

  • Tetra-Pak® is made up of six layers:
    • 74% paperboard
    • 22% polyethylene
    • 4% aluminum foil
  • Benefits include:
    • Perfect for storage of liquid foods and beverages
    • Foil layer insulates and protects
    • Contents remain sterile for a long time
  • Specialist recycling is required due to the multiple layers.

A Sweet Alternative: Tetra Rex®

  • Tetra-Pak® has launched a range of containers that are made from 100% plant-based, renewable materials.
  • The Tetra Rex® range has made all plastic elements using bio-polymers, processed from sugarcane.
  • Even the LDPE film and HDPE lid.
  • The paperboard is certified by the Forest Stewardship Council (FSC).

Metal Effect Card

  • The bright metallic effect can be added to the surface of card by bonding a metallic foil layer.
  • The card can be further processed with the addition of embossing to give it texture.
  • Matte and shiny gloss tones can be blended to create dramatic patterns.
  • Laminated versions can be used for cake boards and other food-grade products.

Moulded Paper Pulp

  • The ubiquitous eggbox is perhaps the most iconic paper pulp packaging product.
  • Pulped paper is a very economical way to create specific forms for protective and secure eco-friendly packaging.
  • It has limited printability but is 100% recyclable.

Plenary

  • Define the difference between paper, card, and board.
  • Explain which materials are ideal for packaging.
  • What qualities would you look for in different boards if you had to package a mobile phone?
  • Which papers and boards are the most absorbent?