Paper and Boards

• Paper


  Made from cellulose fibre, often from waste sugarcane (bagasse)
• Board


  Made from cellulose fibre, often from waste sugarcane (bagasse)
• Sources of cellulose fibre for paper and board

  • Flax
  • Hemp
  • Straw
  • Cotton
  • Bamboo
  • Wood
• Best cellulose fibre for paper


  • Wood, due to quality of fibre length and strength
  • Deciduous and coniferous trees used
• Making paper


  1. Debarked, chipped wood or other cellulose fibre

  2. Acetic acid and other chemicals used to break down lignin

  3. Fillers like clay and calcium carbonate often added

  4. Brightening agents such as bleach

  5. Lots of water
• Making wood free pulp

  1. Solution heated to 140 C to produce fibrous liquid pulp

  2. Dyes and sizes can be added

  3. Minimum 500ml of water makes one A4 sheet of 80gsm photocopy paper

  4. Nearly all water is filtered and reused

  5. Lignin-free fibres called wood free pulp
• Paper qualities


  • Whiteness
  • Opacity
  • Strength
  • Absorbency
  • Finish
  • Cost
• Creating perfect paper


  1. Source of cellulose fibre

  2. Fillers that smooth out finish

  3. Sizing agents that increase absorbency

  4. Calendaring process to create specific thickness and surface finish
• Sizing


  Chemicals added to pulp or sprayed/rolled to base paper to reduce absorbency
• Internal sizing


  Added to pulp and affects paper quality and ability to run smoothly through machines
• Surface sizing


  Added to improve strength, reduce absorbency, and improve printability
• Coated paper


  • Application of surface sizing, reduces ink absorption resulting in brighter, richer and sharper images with deeper blacks
  • Two main coatings: clay to increase smoothness, polyethylene to increase gloss and wet strength
• Uncoated paper


  Not treated with any sealant, allows greater and faster absorption of water or ink, resulting in duller colours and weaker paper
• Paper and board finishes

  • Matte
  • Satin
  • Gloss
  • Textures (felt, wove, vellum)
• Strength factors of base paper

  • Way cellulose fibres bond to each other
  • Strength of cellulose fibres
  • Length of cellulose fibres, longer being stronger
  • Quantity of fillers used, more fillers mean less strength
• Elmendorf tear test


  Measures force used to continue tearing a partially cut and clamped paper/board sample
• Impact resistance


  Measure of strength of paper and board products when subjected to impact force, e.g. packaging damage, indentation from implements
• Weight order of paper and boards

  • 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
• Paper qualities considered depending on end use, e.g. weight for posting, longevity, impact strength, waste and cost efficiency
• GSM


  Paper classified by weight and size, measured in grams per square metre
• Die cutting


  1. Commercially, paper and board can be cut, scored, perforated and creased in one action with a die cutter

  2. Large quantities of identical shapes can be produced quickly

  3. Die is made by skilled technicians using a CAD drawing and laser cut plywood backing plates
• Microns


  Board measured in microns, 1000 µm is 1mm thickness
• Paper-based materials


  Weigh more than 220gsm, classified as boards
• Anatomy of die cutter

  • Metal rules or blades, usually steel, in desired shape in laser cut plywood form
  • Material placed on cutting plate and pressed onto die which cuts, scores, creases or perforates
• Paper size series


  • A series
  • B series
  • C series
• RA series


  Commercial untrimmed sizes, 105% of A series
• Folding and creasing


  • Creasing involves making a line that is permanently present after material is creased or folded, either by hand or with a creasing rule
  • Cellulose fibres become permanently crushed and weakened resulting in the crease line
• SAR series


  115% of A series
• Scoring


  Similar to cutting but blade doesn't go all the way through material, allowing a sharp edge or joint to be created
• Card


  Paper over 220gsm
• Perforations


  Small cuts in paper or board that allow portions to be folded or torn off with good accuracy, usually created with a perforation rule in a die cutter
• Corrugated card


  • Made from one or two flat outer layers called liners and corrugated medium
  • Flexible single layer form otherwise rigid with good strength to weight ratio
  • Shock-absorbing, lightweight, good thermal insulation perfect packaging
• Corrugated or fluted board weight ranges

  • Single wall: 3000 – 5000 µm
  • Double wall: 6000 – 10000 µm
  • Triple wall: 12000 – 15000 µm
• School-based cutting and scoring tools: safety rule, cutting mat, scalpel for cutting, blunt edge knife for scoring
• Perfect package


  • Easy to handle when packing and loading
  • Outer layer printed on for branding and advertising
  • Available in range of sizes
  • Cheap because lower grade raw materials and natural finish
  • Fully recyclable
  • Absorbs moisture
  • Can't pack very heavy as it can tear or collapse when stacked
• Tracing paper


  Semi-transparent, grey, good for tracing ideas and overlaying or transferring one image to another, relatively hard and strong, usually around 40 – 120gsm, acid treated to make 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 sketch pads or large sheets, takes pencil well
• Bleed proof paper


  Designers use for hand drawn marker renderings, does not allow ink or solvent based marker pens to bleed through, highly sized with high opacity gives deep colours, 70gsm
• Cartridge paper


  Creamy off-white colour, used for sketching, surface qualities take drawing media very well, used in Art + DT departments for pens, pastels, pencils, crayons, inks and some paints, slightly textured finish
• Watercolour paper


  Highly absorbent, therefore little or no sizing, withstand large amounts of water and retain structural integrity, remain flat when dried, matte, lightly textured finish