ABCD Scheme

An initiative in the UK designed to classify the type and amount of recycled fibre in a paper product. The scheme grades four types of waste used in paper manufacture, as follows:

A - Woodfree, approved own mill waste (waste that has not left the mill. i.e. mill broke).

B - Woodfree unprinted waste (waste that has left the mill but not reached the consumer, typically from the printer or converter).

C - Woodfree printed waste (post consumer waste, collected from homes, offices etc).

D - Printed mechanical waste (post consumer waste, typically newspapers).

To be classified as recycled the grade has to contain no less than 50% of the total fibre from any combination of the above sources, with the percentages given for each. Therefore Cairngorm is 15A/65B/10C (90% recycled in total with the remainder being virgin fibre).

AOX

Adsorbable Organic Halogens. Collective term for the halogen compounds (chlorine, fluorine, bromine and iodine) bound to organic substances, for example in waste water from the mill. The compounds arise when bleaching with chlorine-containing chemicals, although they can also occur naturally, and are potentially detrimental to water quality.

Bendtsen smoothness

A measure of the surface smoothness of a material, established by gauging the amount of air escaping between a ring-shaped measuring head and the material surface. The results are expressed in millilitres per minute (ml/min). The rougher the surface is, the greater the loss of air and therefore a higher reading is produced. A smoother print finish with a greater degree of dot sharpness can be achieved on material that has a smoother surface.

Black liquor

One of the many sources of power used by pulp and paper mills is gained from the incineration of black liquor. This liquor is essentially liquefied lignin, which has been removed from the cellulose fibre during the cooking stage.

Bleaching

See ECF and TCF.

Blind Embossing

The process by which a raised image is stamped into the material via male/female dies. Debossing is a similar process creating a recessed image.

Blue Angel

A German environmental label, which covers many products, including paper. It takes a ‘cradle to grave’ approach, considering manufacture and disposal as well as product use.

BOD

Biological Oxygen Demand. A measure of the amount of oxygen consumed by micro-organisms in breaking down the organic matter in effluent. Given for a specific period, such as seven days (BOD₇).

Brightness

Brightness is the reflectance of blue light. Results are expressed as a percentage, the higher the percentage, the greater the level of brightness. All Robert Horne measurements are to ISO (International Standards Organisation) methods and standards.

Caliper

Caliper is the thickness of a single sheet. The results are expressed in microns (1000 microns equals 1 millimetre). The instrument used is a Micrometer.

Cast Coated

A paper or board with an extremely high gloss surface. This is achieved by drying the coating in contact with a highly polished and heated metal surface.

CO₂

Carbon Dioxide. A colourless, odourless gas present in the atmosphere as a result of the decay of organic matter and the respiration of living organisms. It is also produced by the combustion of fuels containing carbon (wood, oil, coal, gas etc.) and is used by plants as part of the growing process. Carbon dioxide contributes to the greenhouse effect.

Coated Paper

Paper or board with a coating applied to produce a smooth, ink receptive finish that will enhance the sharpness and gloss of the printed image. Finishes can include gloss, silk or matt.

Coating

A layer of minerals applied to one or both sides of paper or board to improve brightness, gloss and printability. Typically consisting of China clay and/or calcium carbonate combined with starch and latex binder.

COD

Chemical Oxygen Demand. A measure of the amount of oxygen required for the chemical breakdown of organic matter in effluent.

Creasing

In order to achieve a good, crack-free fold it is often necessary to pre-crease the material. Best results are usually obtained when folds are made parallel to the grain and folded into the bead (that is, with the bulge on the inside). Creasing on a litho machine or with the rotary score method will not always give a satisfactory result. It is advisable to experiment with different rule and channel sizes to establish the best combination for a particular material.

CSR

Corporate Social Responsibility. The continuing commitment by business to behave ethically and contribute to economic development while improving the quality of life of the workforce and their families as well as of the local community and society at large, including the environment.

Dandy roll

Wire cylinder used in the papermaking process to create effects such as Laid, as well as watermarks.

Die Cutting

The method used to ‘punch out’ irregular shapes or windows in a sheet. If a window is to be the same shape as the image behind it, the artwork should be planned to make the window slightly smaller to allow for misregister. The dies are usually made by hand from

ECF

Elemental Chlorine Free. Paper pulp bleached without the use of elemental chlorine but instead using some chlorine dioxide, along with non-chlorine agents such as oxygen. Pulps using ECF methods contain up to 0.5kg of AOX per tonne of air-dried pulp.

EMAS

Eco-Management and Audit Scheme. The European Union’s regulated environmental management system. Similar to ISO14001 but also requires public reporting.

Embossing

Most materials will emboss satisfactorily.  Purelypapers' main supplier provides an on-site one-sided embossing service in nine finishes for materials between 135 and 400gm².

EMS

Environmental Management System. A business process that ensures that environmental matters are addressed through a documented system.

Emulsion sealing

This is an overall process often carried out on the last unit of the litho press. Emulsion sealers are used to enable the printed work to progress to other departments more quickly, thus minimising the problem of ink rub. Always check that the sealer used is compatible with subsequent processes.

Eugropa Recycled Mark

Similar to the NAPM scheme but only requires 50% of fibre to be recycled. Europe wide.

European Eco-label

European Union scheme to promote ‘green’ products, including paper. It uses a stringent life cycle analysis to identify where a product might harm the environment (manufacture, distribution, disposal etc.) taking into account various factors such as energy usage and emissions.

Eutrophication

The increased growth of organisms in water, which can be caused by the presence of easily degradable organic matter or nutrients, such as phosphorus and nitrogen.

Felt side

The topside of the sheet as it is being made, i.e. the side that receives any dandy roll pattern.

FFCS

Finnish Forest Certification System. A scheme for auditing forestry operations, taking into account the effects on the environment.

Fibre Source

The types and area of origin of fibrous raw materials.

Film laminating

The process of applying a clear film to the print, for either decorative or protective purposes. Different types of film laminates are available in both Matt and Gloss. Ensure that printing inks are suited to this process (e.g. low wax and stable pigments).

Filler/loading

Minerals added to the paper to improve smoothness and opacity. Typically these are calcium carbonate, china clay and/or titanium dioxide.

Folding Boxboard

A generic term commonly used to describe boards that are made in layers, often consisting of different types of pulp. The top layer is coated and the reverse can either be cream or white.

Formation

Perfect paper formation, when paper is held to the light, has the appearance of ground glass.  Poor formation has the appearance of fibre bundles or ‘cloudiness’. When fibres are uniformly distributed, solid ink coverage will go down smoothly. Poor formation may lead to print mottle.

FSC

Forest Stewardship Council. An international organisation promoting responsible forest management. FSC has developed principles for forest management, which may be used for certifying the management of forest holdings, and a system of tracing, verifying and labelling timber and wood products which originate from FSC-certified forests. For a paper to display the FSC label it must contain a set percentage of approved fibre and the supplier must have the Chain of Custody certificate.

FWA

Fluorescent Whitening Agent (see OBA)

Giga Joules

The S.I. (Système International) unit of work, energy and quantity of heat.

Gloss

Gloss is the surface reflectance value at a given angle. The values quoted by Purelypaper are obtained using the Gardner Gloss Meter, at an angle of 75º. The greater the value, the glossier the surface. The results are expressed as Gardner Gloss units.

Grain Direction

The direction along which the majority of fibres lie is the grain direction. The alignment is parallel to the movement of paper as it travels through the paper machine.

Long Grain (LG). If a sheet is cut LG the long edge is parallel to the grain direction.

Short Grain (SG). If a sheet is cut SG the short edge is parallel to the grain direction.

Usually, the second dimension relates to the grain direction (i.e. 450x640mm is LG, 640x450mm is SG).

Grammage

The weight of a paper or board, given as the weight of a single sheet of one square metre. Expressed as grammes per square metre (gm² or gsm).

Greenhouse Effect

The effect of gases such as carbon dioxide, methane and nitrogen oxides which allow solar radiation to reach the Earth but prevent it from escaping, which causes warming of the atmosphere.

Hot foil blocking/stamping

The process of applying thin pieces of foil (often metallic) onto a material by heat and pressure. It is always advisable to conduct trials with the material you intend to use, as different types of foil are required for different materials.

HSWO

Heat Set Web Offset. A rotary printing process using heat to set the ink. A cylinder transfers the image from the printing plate to blanket to paper at speeds of 30,000 or more impressions per hour.

Inkjet Printing

Printing using a device that builds up the image by the controlled spraying of microscopic droplets of ink.

ISO14001

The standard published by the International Standards Organisation specifying the requirements of an environmental management system.

LA21

Local Agenda 21. The global action plan agreed at the 1992 Earth Summit, which commits nations to sustainable development strategies. In the UK, local authorities have been tasked with co-ordinating LA21.

Laser Printing

Printing using a device in which a light source, typically a laser, is used to expose an image on a photoconductive drum or belt by discharging selected areas. The drum then attracts charged toner particles to these areas, which is then transferred to the paper to which it is ‘fused’ by heat and pressure.

Life Cycle Assessment/Analysis

A method of evaluating the environmental impact of a product ‘from cradle to grave’, including how it’s made, how it’s used and how it’s disposed of.

NAPM Recycled Mark

The National Association of Paper Merchants’ scheme for designating a paper as recycled. To qualify, a grade must contain at least 75% recycled fibre. Converters’ waste, printers’ waste and post consumer waste (from homes and offices) are all allowed (printed or unprinted) but not mill broke - the waste has to have left the mill. The remaining 25% can be mill broke or virgin fibre.

N0

Nitrogen Oxides. Produced during the combustion of fuel and also naturally in the atmosphere. They contribute to the acidification of soil and water and also to ground level ozone.

Nordic Swan

An environmental label encouraging production methods that create minimum environmental impact. Evaluation for paper is based upon strict limits for emissions and effluent from pulp and paper mills.

OBA

Optical Brightening Agent used to brighten the paper. Absorbs UV light and re-emits in the visible spectrum giving the appearance of a whiter or bluer sheet.

Opacity (ISO)

Opacity is the percentage of light that is reflected from the paper surface. The greater the value, the more opaque the material is, therefore reducing the degree of show-through.  The instrument used by Purelypapers' main supplier is the Technidyne Color Touch Model ISO. The results are expressed as a percentage.

Paper/Board

As a general rule, paper/board substances are: up to 170gm² are papers, over 170gm² are boards.

Paper/Board Sizes

The ISO international range of sizes, as used in the UK are (in mm):

A Sizesbasis size A0 = 1m²

A0841x1189

A1549x841

A2420x594

A3297x420

A4210x297

A5148x210

RASizes With small margin for normal trim.

RA0860x1220

RA1610x860

RA2430x610

RA3305x430

SRASizesWith extra margin for trimming bled work.

SRA0900x1280

SRA1640x900

SRA2450x640

SRA3320x450

B Sizes Larger sizes to make optimum use of printing press size.

B01000x1414

B1707x1000

B2500x707

B3354x500

B ‘plus’ Not true B sizes but popular stock items

B0+1020x1440

B1+720x1020

B2+510x720

C Sizes Accommodates finished A Size documents (envelopes etc.)

C3324x458

C4229x324

C5162x229

C6114x162

DL110x220

PEFC

Pan-European Forest Certification Scheme. A scheme for auditing forestry operations, taking into account the effects on the environment.

Porosity

Porosity is the measurement of airflow through the sheet. The instrument used by Purelypapers' main supplier is the Bendtsen apparatus. The results are expressed in millilitres per minute (ml/min). The higher the figure quoted, the more porous the material.

Printing Inks

In relation to offset lithography there are several classifications of ink, including:

Press Open (also Stay Fresh, Duct Fresh). Inks with antioxidants added so that they do not dry on the press rollers or ink duct. May also take longer to dry on the sheet.

Conventional. Inks that dry by a combination of absorption and oxidation.

Fast Setting. Good for quick turnaround of job but with limited rub resistance. Sometimes used for gloss papers and boards.

Positive/Hard Drying. Designed for abrasive materials such as matt-coated papers and uncoated sheets.

Fully Oxidising. Inks that dry by oxidation only and so are suitable for low/non-absorbent materials.

UV. Ink that instantly becomes a solid film when exposed to an intense ultra-violet light.

Ream

A unit of measurement for sheets of paper; normally 500. If the unit of measure is expressed as a "ream" but refers to a quantity other than 500 sheets, then this will normally be indicated in the product description e.g. Motif Premium Multifunctional Paper (Rm=250shts) A4 120 gsm, would indicate that in this case the ream was actually made up of 250 sheets and not 500 sheets as is the norm.

Rigidity

Rigidity is the force required to bend a strip of paper or board through a known angle.  The instrument Purelypaper uses is the Taber stiffness tester using an angle of 15°. The results are expressed in Taber Stiffness Units, with more rigid materials having higher values.

Screen Ruling

The number of lines per inch (lpi) or lines per centimetre (cm^-l) on a half-tone or tint screen. If the figure stated is 'up to', then any screen ruling lower than this will print satisfactorily.  If the figure is stated as 'plus' it means that any screen ruling of this value will print satisfactorily but higher screen rulings can also be used. It is advisable to discuss this with the repro house involved.

SO₂

Sulphur Dioxide. Formed during the combustion of fuels containing sulphur (such as oil and coal). Sulphur dioxide contributes to the acidification of soil and water

Solid Bleached Board

A board made from one layer of bleached pulp so it is white throughout. Will be coated on one side and sometimes both.

Supercalendered

Paper that is processed through a heated pressurised stack of rolls, usually twelve, that compresses and polishes the paper, imparting a gloss.

Surface pH

Surface pH is the degree of acidity/alkalinity of the material's surface. The pH scale ranges from 1 to 14, 1 to 6.9 being acid, 7.1 to 14 being alkali, and 7 being neutral.

Surface sizing

A starch or chemical additive applied to make the paper resistant to water and improve ink hold out.

Sustainable Development

Development which meets the needs of the present without compromising the ability of future generations to meet their own needs.

TCF

Totally Chlorine Free. Paper pulp that is bleached without using chlorine in any form, thus giving an AOX level of zero. The alternative bleaching agents used might be liquid oxygen, hydrogen peroxide or sodium hydroxide.

Thermography

A method of producing a relief effect by applying a powder on to a wet printed image and then introducing heat. It is not recommended if the material will subsequently be laser printed.  However, some companies are successfully UV curing thermographic letterheads to satisfy the laser copying process.

Varnishing

Gloss and matt varnishes are available. For best results on uncoated material, an emulsion sealer should be applied first. There are four ways of varnishing:

Machine. Carried out on the litho machine and puts down a very thin layer of varnish, either overall or in certain areas.

UV. Can be put down on a litho machine fitted with a UV drier and can either varnish overall or in defined areas.

Roller Coat. An overall process with a UV drier.

Silk screen. Carried out on a silk screen machine with a UV drier. With this system it is possible to varnish defined areas with a very thick varnish layer.

Always use inks that are recommended for varnishing. It is best to try to leave narrow channels free from UV varnish in the areas to be creased.

Watermark

A design put into the surface of the paper during manufacture by either a recessed or raised design on the dandy roll.

Whiteness CIE D65

Whiteness relates to the entire visible spectrum. The higher the figure is, the whiter the sheet. The CIE Whiteness formula gives the best correlation between instrumental and visual assessment of whiteness.

Wire side

The wire side is the bottom side of the sheet, next to the wire that conveys the paper fibres and water as the sheet is made.  Each side of the sheet may have slightly different surfaces.

Woodfree

Woodfree is a description of pulp and paper meaning that they contain little or no mechanically ground fibres. Implies that fibres are chemically treated, thereby eliminating lignin (the substance that binds wood fibres together in the tree) and making the product purer, whiter and stronger. Woodfree is an historical papermaking term shortened from 'groundwood-free' and does not denote a paper or pulp made from materials other than wood.

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