Papers & Boards
GCSE — 2.1.2 In-depth Knowledge: Product Design
Categories of papers and boards
Papers and boards are made from wood pulp which originates from trees. Wood pulp is rolled out into thin sheets at an industrial setting called a papermill.
- Paper density is measured by weight in grams per square metre (gsm)
- Paper comes in standard sizes — A0 is the largest, down to A10 (postal stamp size). In schools, A4 and A3 are most common
- Board thickness is measured in microns (1 micron = 1/1000th of a mm)
As a rule of thumb, paper and card above about 200 gsm is classed as board.
Types of paper
| Paper | GSM | Properties | Uses |
|---|---|---|---|
| Tracing paper | 40–90 gsm | Translucent, smooth, non-absorbent | Copying sketches, overlays |
| Layout paper | 50 gsm | Smooth, translucent, cheap | Designing, sketching, developing ideas |
| Copier paper | 80 gsm | Smooth, opaque, clean white, uncoated | Printing, photocopying |
| Cartridge paper | 80–140 gsm | Thick, textured, creamy off-white | Paints, watercolours, pastels, inks |
| Bleed proof paper | 70–100 gsm | Smooth, coated so marker ink does not spread (“bleed”) | Marker pen renderings, design work |
Types of board
| Board | Thickness | Properties | Uses |
|---|---|---|---|
| Corrugated cardboard | ~3000 microns | Strong, lightweight, wavy fluted layers, recyclable, not water-resistant | Packaging |
| Mounting board | ~1400 microns | Rigid, smooth surface, black/white | Framing, architectural modelling |
| Folding boxboard | 300–1699 microns | Stiff, scores and folds well without splitting | Supermarket food packaging |
| Solid white board | ~300–1000 microns | Bleached all the way through, high-quality white surface, prints very well | Premium packaging, e.g. cosmetics and perfume |
| Duplex board | ~300–600 microns | White coated top layer, grey (often recycled) back; cheaper | Food packaging, e.g. cereal boxes |
| Foam board | 3–10 mm | Polystyrene foam core between card faces; very light and rigid | Architectural and display models, mounting work |
Corrugated card comes with different cores: single-wall (one fluted layer), double-wall and triple-wall, getting stronger as layers are added.
Foam board is also covered as a modern material — see Modelling foam board.
Laminating papers, cards and boards
Laminating is adding an additional coating layer to add thickness, weight and strength.
- Food containers and drinks cartons are laminated to retain liquids hygienically and keep produce fresh
- Laminated cardboard is used for book binding
- Most papers and boards are printed on; some are laminated to resist absorbency
Adding surface finishes to papers, cards and boards
Surface finishes can be aesthetic and functional:
- Varnish — adds a glossy finish; part of a logo can be varnished to stand out
- Edge staining — dye applied to edges of a book to improve visual quality
- UV varnishing — produces a high-gloss finish, great for business cards and marketing materials
- Embossing — creates raised patterns or shapes, popular in greetings cards, perfume boxes and invitations
Folding ability and absorbency
Some uses require materials to remain rigid and resist folding (e.g. corrugated cardboard coffee cups — must insulate heat, retain hot liquid, must not leak).
Other products like sandwich containers are die cut, flat-packed items that:
- Have crease lines and fold easily
- Are waxed inside to resist absorbency
Paper and card must be scored before bending to achieve a clean fold.
Greener solutions
A lot of paper-, card- and board-based packaging is designed to be fully recycled, providing a ‘cradle to cradle’ approach:
- Reduces waste and the need for new materials
- Reusability is high — containers can be washed and reused
- Paper is fully recyclable, reducing the need for wood fibres from trees