Paper – Glossary of Terms
There are many terms used when working with paper – here is a
selection of some useful definitions:
Acid Free Paper
A paper which does not contain any free acid. Special precautions
are taken during manufacture to eliminate acid in order to increase
the longevity of the finished paper and to provide a sheet that is
suitable for contact with metals.
Antique
A quality bulky paper, particularly opaque, with a rougher surface
finish. It can be made in white or in colours, be deckle edged, and
either laid or wove. A good printing surface is a feature of this grade
which is often used for quality books.
Art Paper
This is a general term for higher quality woodfree coated papers
which have a highly polished surface. Today the term is less used
because of the introduction of more categories in the sector.
However ‘real art’ is still used for those woodfree coated papers
considered to be of the highest quality.
Base Paper
Name given to the base sheet which is intended to be off-machine
coated or converted.
Blade Coated Paper

Paper coated by a process in which the freshly applied wet coating is
smoothed and the excess removed by a thin flexible metal blade
which bears on the coated surface.

Bleaching

A chemical treatment used to whiten, brighten and improve the
performance of pulp.

Boards
Term applied to a paper above an accepted weight. The accepted
cross-over point from paper to boards varies but in general would be
around 180gsm. Below this weight are papers above this weight
would be boards.
Broke
Paper, which during the paper making process becomes suitable
only for repulping e.g. trimmings or paper that is out of specification.
This re-used material which never left the mill is not regarded as
recycled.
Bulk
A term applied to the substance, thickness and feel of paper.
Calendered
Paper subjected to smoothing and polishing between stacks of highly
polished steam rollers (calenders), which can form part of the dry end
of the paper machine.
Cast Coating
A method of drying coated paper by contact of the freshly coated
surface with a highly polished chromium plated heated surface. Cast
coated papers have an extremely high gloss finish for top quality
printing. The finish is obtained by the coating mix solidifying while in
contact with the polished surface resulting in a similar polished
surface to the paper.
CBS1
Used in bank credit forms Clearing Banks Specification 1 must be
95gsm paper and of determined rigidity, surface smoothness, fold
and strength characteristics. It’s chemically treated to prevent
tampering.
CBS2
Used in bank credit forms Clearing Banks Specification 2 must be an
80/85gsm paper and of determined rigidity, surface smoothness, fold
and strength characteristics, with low background fluorescence for
OCR readability.
Chemical Pulp
Pulp made by means of chemicals that dissolve the bonding agent,
called lignin, within the wood to separate the fibres.
Constat
A contraction of the words ‘continuous stationery’.
Cutting to Register
Operation of slitting and cutting watermarked paper so that the
watermark design falls in a given position in every sheet.
Double Coating
Coating of paper or board twice on one or both sides.
ECF (Elemental Chlorine Free)
A common definition for pulp bleached without using elemental
chlorine. Originally any of the bleaching techniques for chemical pulp,
when no molecular (elemental) chlorine is used.
Fastness
Resistance to colour fading.
Gloss
Gloss can refer to the reflectivity of paper itself or of the printed result
on it. Gloss of paper is measured by using a Gardner gloss meter,
which measures reflected light at an angle of 75 degrees, and is
expressed in Gardner gloss units – the higher the number the glossier
the paper surface.
Grain Direction
During manufacture the fibres in a web of paper naturally take up an
alignment roughly parallel to the direction of travel of the web on the
papermaking machine and this becomes the grain direction.
Once guillotined down to sheet form, papers are called ‘long grain’ if
the fibres are parallel to the long edge of the sheet, or short grain if
parallel to the short edge.
Grain direction can affect stiffness, folding, creasing and printing
characteristics.
Graphic Papers
Papers for printing and writing.
Gsm or gm2 or g/m2
These all mean ‘grams per square metre’ and are a measure of the
weight of a paper. For example if an 80gsm paper was in a sheet
size of 1000mm x 1000mm i.e. a square metre one sheet would
weigh 80 grams.
Hickey
A spot on a printed sheet caused by dust, lint or ink imperfections;
particularly noticeable on solids and half tones.
Integrated Mill
A mill which starts with logs or wood chips and produces wood pulp
which it then processes to make paper without intermediate drying.
Ivory Board
High quality board made in white or colours with a bright clear
appearance, particularly used for visiting cards and similar high
quality printed work.
Lick Coating
A light form of mineral coating, achieved by supplying the surface
sizing press of the papermaking machine with coating material
instead of normal surface sizing solution.
Lightweight Coated (LWC)
Coated paper below approximately 60 gsm.
Matt Paper
A coated paper with a dull smooth finish.
Mechanical Pulp
Pulp produced using a non-chemical process and instead using a
grinding process. Papers made from mechanical pulp often have
good opacity and bulk but yellow more quickly than paper produced
from chemically made pulp. Newspapers are often printed on papers
having a proportion of mechanical pulp.
NCR
An acronym meaning ‘no carbon required’ referring to a noncarbonless paper originally introduced by the National Cash Register
Company but which is now more commonly referred to as carbonless
paper.
Neutral Sized Paper
Paper sized with neutral size i.e. neither acidic nor alkaline. Neutral
sizing gives the paper enhanced longevity.
Opacity
The extent to which a paper is capable of obscuring matter printed on
the other side or on an underlying page. A paper with good opacity is
one on which the printing on one side cannot be seen from the other
under normal conditions. Usually expressed as a percentage (%).
Papyrus
An ancient writing material made from stems of the papyrus plant.
Although the word ‘paper’ is derived from papyrus, papyrus itself is
not paper in the normal sense.
Envelope – Glossary of Terms
There are many terms used when working with envelopes –
here is a selection of some useful definitions:
Back Flap
Reverse side of a wallet or banker.
Bang Tail
Special style of wallet, incorporating a perforated flap, extending
from the throat.
Banker
Style with an opening on the long edge, and a diamond shape flap.
Described as either high cut or low cut depending on the throat.
Basket Weave
Paper with a weave effect finish traditionally used for heavyweight
manilla papers.
Blank Fed
Envelope manufacture using sheets of paper.
Bleed
Where the print runs off the edge of the paper.
Board Backed
Generally a pocket style, made with a cardboard back to provide a
rigid envelope.
Business Reply (BRE)
A reply envelope with pre-paid postage using a business reply
licence. Most often used with business to business mailings.
Chevron Flap
Where the contour on the top flap of the envelope matches the
leading edge of the back flap.
Colour Washing
Printing technique used on the inside or outside of an envelope to
give a tinted or colour effect.
Constanzia Wallet
A wallet construction, but with the side seams folded on the outside
of the backflaps. Used primarily for mailing wallets.
Face
The front of an envelope.
Glassine
Paper based material, used for windows and some photo
envelopes
Gumming
A strip of gum applied to the flap that needs to be dampened to
help seal the envelope.
Gusset Pocket
An open end envelope with expandable sides.
Kraft
Strong, glazed manilla paper. Also produced in white and bleached
kraft.
Landscape
An envelope format where the longest side of the window runs
parallel to the long edge of the envelope.
Machine Enclosable
An envelope that runs efficiently through an automatic mailing
machine (see mailing wallet).
Machine Glazed (MG)
Smooth finish on one side of the paper, particularly common on
manilla paper.
Mailing Wallet
A style of envelope that can be used in an automatic mailing
machine.
Mirror Gummed
Remoistenable gum on both the flap and the backflap for extra
security.
Multi-Tuck
Pocket with an ungummed internal flap that folds over for security
but can be opened for postal inspection.
Opacity
The degree of show through or transparency of the paper, i.e. an
envelope with good opacity will not show the contents enclosed.
Opaque
Printed solid, or design inside an envelope for security.
Out Turns
Envelopes that have been taken from the print run and sent to the
client.
Overprint
Printing onto already manufactured envelopes.
Pocket
Envelope style with one side or centre seam, a bottom flap and an
opening on the short side.
Porosity
The measure of air in the paper that allows absorption of ink. The
degree of porosity can affect the quality of the printing, and can
also affect the efficiency on some automated enclosing machines.
Portrait
An upright envelope where the long side of the window is parallel
to the short side of the envelope.
Post Office Preferred
Series of recommendations for envelopes, set by International
Postal Administrators.
Pull-Tab
A cut out strip which can be pulled to reveal a gimmick or open an
envelope.
Reel Fed
High-speed envelope manufacturing technique, using reels of
paper.
Re-Sealable
Latex gum on the flap and back of the envelope, that gives instant
adhesion but can be opened and closed several times for postal
inspection.
Score Line
Fold between the flap and the throat of wallets and pockets.
Security Slits
Lines scored on the outer flap of self-seal envelopes only, which
split the flap in several places when it is opened. This makes it
possible to detect if the envelope has been tampered with.
Security Wash
See Opaque.
Self-Seal
Two strips of latex on the envelope flaps that seal with each other
on contact.
Shoulder
Top of the side flaps on a wallet. A critical design aspect for most
automated inserting machines.
Side Flap/Seam
Two seams on a wallet/banker, gummed to the back flap.
Superseal
Envelope with self-adhesive flaps, protected by a release strip to
give extended shelf life.
Throat
Gap between the score line and the back flap of a wallet. A critical
design aspect for most automated inserting machines.
Thumb Cut
Shape cut from a topless pocket or wallet, to enable easy access
to the contents.
Topless
Pocket or wallet style without a flap, although a lip may be left.
Wallet
Envelope style with two side seams and the opening on the long
edge.
Part Mechanical
A paper containing up to 50% mechanical pulp, the remainder being
chemical pulp.
RA Series
An agreed range of paper sizes.
Examples: RA1 = 610 x 860mm RA2 = 430 x 610mm RA3 = 305 x
430mm
Reel
A continuous length of paper wound on a core, irrespective of
diameter, width or weight. Reels can be rewound into smaller reels or
slit into coils.
Reel to Reel
A machine on which the material is supplied in reel form and comes
off the machine also in reel form.
Runnability
The ability of a paper and board to perform and run through a printing
press or on converting machinery without problems.
Self Contained Carbonless
A carbonless type paper which can generate an image itself through
the application of pressure. Self contained carbonless papers work
without the need for other top, middle or bottom carbonless sheets.
SRA Series
An agreed range of paper sizes.
Examples: SRA1 = 640 x 900mm SRA2 = 450 x 640mm SRA3 = 320
x 450mm
Substance
The weight of paper or board, shown by scales, taken from a sample.
The weight is almost entirely defined by grammage per square metre
of a single sheet (g/m2).
TCF (Totally Chlorine Free)
Pulp produced without any chlorine or chlorinated chemical
compounds.
Woodfree
A pulp or paper which contains no mechanical wood pulp. In
commercial practice a small percentage of mechanical fibre is usually
acceptable. It does not denote paper or pulp made from materials
other than wood.