Rugby School Thailand Design & Technology Senior School

8.1 Papers and Boards

Specification content

Papers and boards

• The working properties, stock forms and sizes, common uses and environmental impact of the following:

– copier paper

– card

– corrugated card

– bleached card

– mount board

– duplex card

– moulded paper pulp.

By the end of this unit you should have developed a knowledge and understanding of:

where paper comes from and how pulp is converted into workable materials
the common stock sizes and forms of paper and card,
the properties of paper and board,
the differences between paper, card and board
how boards can be laminated to other materials enhance their properties.
common uses for different types of paper and board

Glossary:

Compliant - Easy to manipulate / work with

GSM - Grams per square meter

ISO - International standards

Laminated - Layered

Paper based (compliant) products can be put into three categories.

*Note that there are various definitions of what constitutes paper, card or board:

Paper

Thin, with a weight up to 200GSM

Cartridge, tracing, layout, Watercolour

Card

Heavier with a weight over 200GSM

Duplex card, Box card

Board

Thicker than card and up to 500+ GSM

Mounting board, foam board

Sources and origins

Paper, card and board are made from wood pulp which is extracted from the fibres found in wood. See the section on wood and timber for more information.

Wood is made up of cellulose fibres which are glued together with a natural product called lignin. In order to make paper pulp, the lignin needs to be removed so that the cellulose fibres can bind together to form paper.

The wood is crushed and the extracted material is 95% water based pulp which looks a bit like milk.

It is then passed through dryers and rollers to achieve the basic quality of paper.

Wood pulp

Lignin and Cellulose

Stock forms of paper

Paper and board comes in sizes that correspond to each other called the International Standards Organization (ISO) system.

Common stock paper sizes

The A size is the standard for most general printing and stationary. Each size can be halved while increasing the A number. For example:
A0 is the largest standard stock size; often used for architectural drawings.
A1 is often used for artwork and posters
A2 is used for smaller artwork
A3 is a standard size used for D&T portfolios.
A4 is usually used for business stationery, brochures, booklets etc.
A5 is commonly used for smaller items such as leaflets/flyers etc.
A6 is the international postcard size.
A7 for labels etc.
A8 for business cards

The thickness of paper and thin card is measured in microns: a micron is 1/1000th of a millimeter. However, board such as corrugated cardboard can be quite a few millimeters thick.

Paper and Card Properties

Optical properties of paper products

As all paper products are derived from the same material, what makes them different are their optical and surface properties as well as their weight.

Cellulose is ‘jelly-like’ with translucent qualities which, when compressed lightly, makes paper that can allow light to pass through it.

Layout paper and tracing paper are examples of this.

To make paper more opaque, the pulp is compressed further making it less translucent, and adding thickness makes it more opaque. Paper can be coloured or have additional layers of materials added to it.

Optical Properties also include brightness, colour, opacity and gloss.

Opacity refers to how much you can ‘see through’ the paper.

Gloss, glare, finish and smoothness refer to how glossy or reflective the paper is while finish refers to the general surface characteristics of the paper e.g. rough

Strength and durability refer to how strong the paper is. Paper strength is dependent on thickness and greatly affected by moisture.

Tensile strength refers to how strong the paper is when stretched while bending strength is how flexible the paper or board is.

Porosity is how much the paper will absorb moisture. For example, greaseproof paper has little porosity.

Changing the finish

We need a variety of different finishes on paper but how do we get them from the same paper material?

Coating

In order to get a smooth finish on paper or card it is sprayed with china clay or chalk.

sizing

The addition of a sizing agent improves the ability of the paper or card to accept ink by sealing the absorbency of the surface. Both coating and sizing directly affect brightness.

Laminating

Paper and card can also be laminated. Layers of thin card are stuck together. Depending on now many layers are stuck together you can change the qualities of the card.

Key concepts

Cost

Basically people choose paper based on cost which is why newsprint for newspapers is so cheap, but photo paper is expensive.

finish

This is how the material looks and feels and varies depending on what you are using it for.

strength

How strong the paper is. Newsprint is cheap and doesn’t need to last long but packaging for expensive perfume needs to be much stronger.

brightness

AKA Whiteness

Basically how white the paper is and, as it reflects light, it will appear brighter.

thickness

How thick the paper is, as it gets thicker it becomes card then board.

Summary

Weight or thickness define the material as paper or board.
Card is another name for board which is thick paper.
The difference between paper and card or board is the thickness or weight.
Paper is sold by weight in grams per square metre (gsm) up to approximately 200 gsm at which point it becomes card/board.
Board is often defined by its thickness or layers which can be measured in microns or millimeters for thicker boards.
There are 1000 microns in 1mm and a typical birthday card is 300 microns thick compared to the thin paper in your text book which is 90 microns thick.
Here is the list of common paper products in order of their GSM.

Paper - up to 200 GSM

Newsprint (35-50GSM)

is very thin and used for newspapers.

Layout Paper (50GSM)

is used for sketching and development work.

It is thin enough to trace over existing drawings.

Layout paper is used by designers particularly in advertising where it can be used to traced over previous sketches building up concept ideas with each layer.

Tracing Paper (60-90GSM)

Is translucent and its hard surface allows ink to be scraped off. Tracing paper and drafting film are more translucent than layout paper and used for tracing and for technical drawings respectively.

Cartridge Paper (120-150GSM)

is higher quality drawing paper, cream and slightly textured.

Cartridge paper is thicker than printer paper but not as thick as watercolour paper and often has a textured surface to encourage the transfer of pencil, chalk and pastels. It is the paper of choice for artists but can also be used for high quality letter printing/writing.

Photocopier Paper (80GSM)

is cheap when bought in bulk.

Printer paper is used extensively in printers and laser copiers etc. It has a

smooth surface and is also ideal for general writing and drawing.

Sugar Paper (100GSM)

is available in a range of colours and is often used as the backing for wall displays in school. The colours are easily bleached out.

Bleedproof paper (120-150GSM)

is used for marker work as it has a barrier which stops ink from ‘bleeding through’ the paper.

Bleedproof paper has a protective layer on the underside to stop ink bleeding into the next sheet. Often used for marker work.

Watercolour paper

Watercolour paper is a thick paper which, unlike cartridge paper, has better resistance to wrinkling and creasing when wet.

There are three main textures available in watercolour papers.

Hot pressed paper with a hard, smooth surface.
Cold pressed papers with a rougher surface but better absorption
A third type, which is rougher than cold pressed

Recycled paper

Where does recycled paper come from?

We saw that paper products are made from pulp which originally derived from wood, but it can also be recycled from waste-paper products.

The pulp is a grey brown colour and needs to be bleached to make white paper which adds to the expense, but it needs to be white if it is to be printed on so the colours are not compromised.

Inkjet Card (120-280GSM)

is a high-quality card treated so it can go through all types of inkjet printers.

Cardboard (125-300GSM)

is a cheap recyclable stiff board used for packaging.

Whiteboard (200-400GSM)

is a strong bleached board ideal for printing onto.

Duplex Board (230-420GSM)

is a cheaper alternative to whiteboard, often

brown on one side but with a white surface ready for printing.

Corrugated cardboard (250+GSM)

contains two or more layers with fluted

sections which add strength to the card without a huge increase in weight.

500GSM+

is very thick card such as mounting board and after this point further thickness would be achieved by laminating different materials.

Manufacturing with paper and board

Papers and boards are commonly used in the manufacture of packaging, cups and magazines.

All of these products require materials that will meet the functional requirements of packaging.

Card can have a metallic or holographic finish, be mirrored or pearlescent. Bank notes and credit cards can have metallic strips embedded in them as well as holographic security marks.

Paper cups

Magazine

Packaging

The term carton board covers a range of packaging materials from single layer card for cereal packages and soft drinks cartons to multi layered and corrugated card for shoe boxes and packaging for electrical goods. Thinner carton board usually has one printable side and one which is unbleached (usually grey or brown).

Cereal package

Shoe box

Product packaging

Foil backed card

Foil backed card is used for the lids in take out food containers. It has the benefit of being a cheap card product while offering insulation, a wipe clean surface, some water resistance and stops the card side from contaminating the food. The metal coating is aluminium.

Foam Board

Another type of laminated board, Foam Board is a multi layer board

made up of two outer layers of card with a foam centre. It is used for

display boards and more commonly used for architectural models.

Correx Board (often the referred to as Corriflute)

Correx Board (often the referred to as Corriflute) looks similar to corrugated cardboard but is made of thermoplastic giving it better water resistance while remaining lightweight.

While it is not a paper-based product, it is often printed on or used to apply a printed or laminated paper to so is included for reference.

Summary

Paper based products are derived from wool pulp.

Wood pulp is transparent so lightly compressed pulp results in tracing paper and other translucent papers.

As paper gets thicker it is classed as card then board.

Card can be laminated with other materials to improve its properties.

Duplex card has two different sides; these can be different colours or different materials such as a plastic laminate or metallic material on one side as in the tops of takeaway containers or box card which is grey on one side and white on the other.

Corrugated card is very strong and used for packaging. You might be surprised at just how strong and versatile it is…

How strong can card be?..

Cardboard cafe Mumbai

Cardboard house exhibition

Revision Notes

All paper and board-based products are derived from wood fibres so refer to that section for the ecological and social footprint.

Paper, card and board are essentially all the same material. It is the weight or thickness that dictates their classification.
Remember the names of the materials rather than the classification i.e. cardboard is clearly a board.
Weight is measured in GSM.
Thickness is measured in microns.
Paper and board can be corrugated, laminated, coated, varnished,
duplex, textured and more.
Familiarise yourself with a range of everyday paper and board-based products and how they are made or finished.

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