See our special sections for more in-depth detailed
explanations of:
Offset Lithography
Four Colour (CMYK)
Process Printing
Paper Sizes
Art Paper
Paper which has a coating usually of china clay.
It can be gloss or matt and is suitable for jobs requiring a fine
finish such as colour brochures and annual reports.
Artwork
Originally the physical art (Sometimes referred
to as Camera-Ready Artwork or Mechanical) prepared by the designer
and including type, graphics and other originals.
This was used by the printer to produce the printing plates.
Today the artwork exists almost wholly in electronic
form. Photographs and illustrations are input to the computer using
a scanner. All the elements are assembled
using page layout software. Proofs can be made using colour laser
or inkjet printers. The computer then separates the 'artwork' and
produces high resolution films from which the printing plates are
made.
Backed Up
When the reverse of a sheet is printed. See Work
& Turn.
Bank
A lightweight paper, usually less than 60gsm.
Bleed
Printed area which extends off the trimmed area.
It is not possible to print all the way to the
edge of the paper sheet. To achieve this effect it is necessary
to print a larger area than is required and then trim the paper
down. Typically a designer would allow an extra 3mm of bleed to
colour and image areas to allow for a little leeway when trimming.
Blind Embossing
A type of embossing where
no ink is used. The design or text is only visible as a raised
area on the paper.
Bond
A basic paper, often used for copying or laser
printers. The better quality bond papers, with higher rag content,
can be used for letterheads.
Calendered Paper
Paper which has passed through hardened rollers
during manufacture to produce a smooth surface.
Cartridge Paper
A heavy, textured paper often used for drawing.
CMYK
Shorthand for the colours used in Four
Colour Process Printing. Cyan, Yellow, Magenta and Black.
Coated
Paper which has received a coating to achieve
a special finish. See Art Paper.
Collating
The process of assembling the various sections
or sheets of a document in the correct order.
Colour Separation
Separating a colour job into the elements required
for printing. See Four Colour Process
Printing.
Crease
A printed job can be creased mechanically to
make folding easier. There are times when you might want a printed
piece delivered flat for ease of storage and then do the folding
yourself, manually.
Cromalin
The brand name of a colour proofing system
produced by Du Pont.
Cyan
The blue colour used in Four
Colour Process Printing.
DIC
The brand name of a colour matching system produced
by Dainippon Ink
& Chemicals, Inc. A range of inks are specified and identified
by number to produce standard results across the industry.
Digital Printing
A recent development has entered the market
in the shape of digital printing. These systems work directly from
electronic data and avoid the intermediate stage of films.
They are very cost effective for short runs. The quality obtainable
is not yet up to lithography standards
but is improving steadily and is adequate for many purposes. Because
these systems use an inherently four colour
process there is no cost saving to be made from using one-
or two-colour designs. Two popular digital machines are the Indigo
E-Print and Heidelberg Quickmaster.
Drilling
Making the holes in paper for use in a ring
binder. Drills can neatly perforate a much greater thickness of
paper than can the kind of hole punch you have in the office.
Dummy (1)
A plain white mock-up of a booklet or brochure — Not
printed but made up using the intended stock.
Most printers will make up a dummy if you ask nicely. This is the
best way to get a feel for the finished product.
Dummy (2)
A mock-up produced by the designer to show how
the finished job will look. This will usually involve colour prints
from various sources and will therefore not be on the intended stock.
Duotone
A two-colour halftone sometimes
used in Two Colour Printing. Produces a tinted effect using a black & white original.
Embossing
Stamping a design into the paper to produce
a raised effect. See Blind Embossing.
Films
Films are produced by an imagesetter from
the artwork. They are used to produce
the printing plates by a photochemical process. There is one separated
film for each ink used. See Four Colour
Process Printing.
Finishing
Any process that follows the actual printing.
Can include folding, creasing, stitching,
binding and the like.
Focoltone
The brand name of a colour matching system produced
by Focoltone International Ltd. A range of inks are specified and
identified by number to produce standard results across the industry.
Folio
Printer's technical term for what the rest of
the world calls a page number.
Four Colour Process Printing
The most common system for producing full colour
print. Originally the artwork and originals were
separated using filters and four printing plates were produced.
The four ink colours are Cyan (Blue), Magenta
(Red),Yellow and Black — often referred to as CMYK.
Because the inks used are translucent, they can be overprinted
and combined in a variety of different proportions to produce a
wide range of colours.
The vast majority of magazines and colour books
are produced using four-colour process.
For a more detailed look at four colour process
printing, see our Four Colour
Process Printing page.
Gravure
A not very common printing process where the
image area is etched below the surface of the plate (An intaglio process).
Gravure is most often used for either very high quality or long
run printing. The web version is sometimes
referred to as rotogravure.
gsm
Abbreviation for grams per square metre. This
indicates the weight of paper or other stock. For example; A typical
photocopier paper would be 80 gsm — a good letterhead paper
might be 100 gsm — a postcard would be about 250 gsm.
Halftone
The method of producing a range of tones, such
as a photograph or tinted area, by dividing the image into a series
of dots. Dark areas have relatively big dots, close together. Light
areas have small dots surrounded by white space. The number of
dots used determines the quality of the image produced. In a newspaper
the halftone dots are easily visible to the naked eye — the
screen used can often be as coarse as 60 dpi (dots per inch). A
colour magazine would typically use a screen of 150 dpi — An
art book, 175 dpi or finer.
A halftone screen can be applied to a solid
colour in order to produce tints of that colour.
Imagesetter
Output device used to produce separated films from
digital artwork. It can be thought
of as a very high resolution printer. Most systems use the Postscript page
description system.
Imposition
The layout of pages on the printed sheet so
that they are in the correct order when the sheet is folded up
and trimmed. Imagine a 16-page A5 leaflet
printed on a single SRA2 sheet. The
sheet is folded in half three times before trimming and stitching.
If you look at the printed, unfolded sheet you will see that, for
example, page 2 is adjacent to page 15 and half the pages are upside
down! There are many different imposition layouts — some
of them very complex.
Insert
Technical term for those irritating adverts
that fall to the floor when you open a magazine. An insert is usually
not secured to the main book or brochure and is sometimes referred
to as a loose insert for obvious reasons.
Intaglio
A printing process where the image is engraved
below the surface of the printing plate such as gravure.
Interleaving
Introducing alternate sheets of blank paper
between the printed sheets as they come off the press to prevent set
off.
Lamination
A plastic coating which protects the printed
surface and usually gives a high gloss finish. Most paperback books
have laminated covers.
Laid Paper
Uncoated paper often used for business stationery
which has a textured pattern of parallel lines similar to hand
made paper. Compare to Wove Paper.
Landscape
The orientation of the page so that the long
edge is along the bottom. Sometimes referred to as horizontal.
The opposite of portrait.
Line artwork
Artwork which contains
no halftones such as company symbols
or simple diagrams.
Lithography
By far the most common type of commercial printing.
See our Offset
Lithography page for more detailed information.
Make Ready
The processes involved in getting a press ready
for a print run.
Machine Minder
The person who actually runs the press. The
quality of a printed job is often dependent on the skill of the
machine minder.
Offset Printing
Printing system where the paper does not come
into contact with the printing plate. The ink is transferred from
the plate to a blanket cylinder and then to the paper.
See our detailed
description of Offset Lithography. With diagrams!
Originals
The basic elements of the artwork.
Includes photographs on print or transparency,
illustrations, line artwork etc.
Overs
A quantity of printed material in excess of
the amount ordered. It was once usual practice for a printer to
charge pro rata for overs. This is much less common nowadays.
Pantone
The brand name of a colour matching system produced
by Pantone, Inc of the USA. A large range of inks are specified
and identified by number to produce standard results across the
industry.
A reference such as PAN199 indicates a colour
in the Pantone range, in this case a bright red. In a colour swatch
book the number PAN199C would indicate how the colour looks when
printed on Coated or glossy stock.
PAN199U indicates how the same ink appears when printed on Uncoated
or matt stock. Sometimes the difference can be quite dramatic.
It is worth remembering that Pantone inks provide
a much greater range of colours than can be achieved using CMYK.
This is important if trying to match work printed in four
colour process with that printed in special
colours.
Paper Sizes
The most common system of paper sizes in Europe
is the ISO standard. Most people are familiar with the A series
which includes A4 the usual letterhead size. The C series is for
envelopes — A C4 envelope being ideal for holding an A4 sheet.
There is also a B series which provides intermediate sizes for
the A series but this is rarely used.
The aspect ratio of ISO paper sheets is 1 to
1.4142 (The square root of 2). This gives them a unique property:
If you cut a sheet into two the resulting halves are the same proportion
as the original. In other words a sheet of A4 when halved gives
you two sheets of A5. All A size papers have the same proportions.
The largest sheet in this series is A0 which is 841mm x 1189mm
and just happens to be one square metre in area (ISO paper sizes
are rounded to the nearest millimetre).
Two other series which you may come across are
RA and SRA which are used by printers. They are slightly larger
than the A series to provide for grip, trim and bleed.
See our chart of paper
sizes for more details.
Of course you can use any size of paper you
choose. However, most paper merchants supply ISO sized stock so
it is most cost effective to stay with A sizes.
Perfect Binding
A type of book binding where the pages are held
in the spine by glue. Many magazines and most paperback books are
perfect bound.
Perfecting
Printing both sides of a sheet in one pass through
the press.
Portrait
The orientation of the page so that the short
edge is along the bottom. Sometimes referred to as vertical. The
opposite of landscape.
Postscript
The brand name of a software standard created
by Adobe. It is a page description language which is used by most
graphics software and output devices to combine text, pictures
and graphical elements into an electronic document and create output
which can be used by the printer.
Printing Plate
The physical plate which carries the image.
These can be made from a variety of materials. At the cheaper end
of the market there are paper plates which are designed to be used
once and thrown away. They are very economic for short runs such
as small quantities of stationery.
Progressives
A set of proofs which
show the different inks separately and combined in various permutations.
Proof
A test print produced to show what the finished
product will look like. These can be made in a variety of different
ways and at different stages of the production process. The simplest
form is a colour laser or inkjet print which can create a rough
impression. It should be remembered that at this point there are
still a number of stages through which the data has to pass and
therefore a laser print cannot be relied upon as an accurate proofing
method.
Photochemical proofing systems like Cromalin have
for many years been the most popular method. The colour print is
produced directly from the separated films and therefore gives
an accurate interpretation. Sometimes the colours can be even sharper
and more vivid than can be achieved on the press and there is a
danger of creating unrealistic expectations in the client.
The most accurate method is a wet proof. This
involves using a special proofing press designed for very short
runs and actually printing a quantity of sheets using the real
stock and real inks. Of course this requires producing the films
and plates, not to mention the cost of Make
Ready which makes wet proofing a very expensive option, particularly
if corrections are required. This is a bad time to start looking
for typographical errors.
Increasingly popular are digital proofing systems
which aim to simulate the Cromalin type proof. They are essentially
very high resolution colour printers which make use of colour management
techniques for their accuracy.
Whatever system you choose it is certain that
proofing is a good thing which can save a lot of heartache and
cost later on. Sad to say, many clients with an eye on the budget
tend to regard proofing as an unnecessary expense. "There's
always time for a reprint".
Register
When printing with two or more colours it is
necessary to align the different plates.
This is known as register. On the edges of an untrimmed sheet you
will see small target shapes called register marks which are used
for accurate positioning. A printed piece which is out of register
will have an unfocussed, blurred look.
Run-on
Often when a printing price is quoted it is
given as a figure for the basic job plus a figure for additional
copies. For example the price may be 2000 copies at £300
with £25 for a 500 run-on. This enables you to calculate
a range of prices for different quantities.
It is very important to note that the run-on
price is for copies printed at the same time as the main run. For
instance, in the example given, you could not have 2000 copies
today and then expect to have another 500 at some future date for
just £25. In many cases the set-up and Make
Ready charges represent a large proportion of the print cost.
Rotogravure
The web version
of gravure.
Saddle Stitch
A simple way of assembling a small booklet or
magazine with a wire stitch through the fold. You may call it stapling
but printers call it stitching.
Scanner
A device for turning a piece of artwork into
a digital form. Transparencies, prints and illustrations are scanned
so that they can be accessed by software designed for image manipulation
and page make-up. For many years the industry standard was the
drum scanner, a rotary system which produced very high-resolution
scans. Recently flat-bed scanners, such as you might use with a
PC, have risen dramatically in quality to the point where the better
models are suitable even for high-end work.
Score
Heavier paper and boards need to be scored with
a rule to make folding easier.
Screen Printing
This is a process where the ink is transferred
to the printing surface by being squeezed through a fine fabric
sheet stretched on a frame. The screen carries a stencil which
defines the image area. The process can be manual or mechanical
but is most suitable for short runs. Screen printing is usually
used for large poster work and display material. It comes into
its own when printing to difficult or unusual surfaces such as
clothing or plastic objects. It is often referred to as silkscreen
printing although the screens are generally made from artificial
fibres.
Section
A folded sheet which is assembled with others
to make up a book. For example an A2 sheet
will provide a section of eight A4 pages
when folded twice. A 20-page booklet would therefore require two
8-page sections and one 4-page section. These sections are then saddle-stitched together.
Larger booklets of, say, more than sixty pages could be perfect
bound.
Set-Off
A printing fault where ink transfers from a
sheet to the one below as it leaves the press creating an undesirable
ghost image. This can be cured if necessary by interleaving.
The machine minder should be able to correct the problem.
Sheet Fed
A press which prints by taking up one sheet
at a time. This is the system you are most likely to come across.
The opposite of web.
Special Colours
This refers to colours which are produced using
specially mixed inks from one of the commercially available colour
ranges such as Pantone, DIC or Focoltone.
They are most commonly used when using Two
Colour Printing.
To print colours outside the range of four
colour process it is necessary to use special inks. If for
example the exact colour of a company logo could not be achieved
from a CMYK mix then it would be
necessary to print a fifth plate with
the special ink. It is not unusual, where an elaborate effect
is required, to print in six or more colours. There are presses
which are capable of printing eight different plates in a single
run through the machine.
It is worth bearing in mind when choosing a
colour for a company logo that sooner or later you will want to
print a colour brochure using four colour
process. A vivid ink which you have chosen from the Pantone book
may not have an acceptable CMYK equivalent.
You may be forced to change the company colour or swallow the ongoing
expense of a fifth plate.
Stock
A general term for any paper or board which
is used as a printed surface.
Three Colour Printing
Theoretically it is possible to produce an adequate
range of colours using just Cyan, Magenta and Yellow. In Four
Colour Process Printing the black plate adds shade and depth
reducing the amount of ink required. Today this system is very
rare.
Three colour printing may also refer to the
use of three special inks or black combined with two specials.
Transparency
The preferred medium for photographs intended
for printing. Transparencies generally have sharper images and
better colour than photographic prints. The three most common sizes
are 'five-by-four', 'two-and-a-quarter' (both in inches) and 35mm — the
same size as your holiday slides.
Two Colour Printing
Two colour printing is commonly used for stationery
because of its cost-effectiveness. The typical design includes
a special colour such as a Pantone ink
along with black. The special ink is for the 'company colour' for
use on the logo and the black is for text. In addition, tints of
both inks could be used to produce variations of the colour and
greys respectively. For example, if a strong blue is chosen as
the main colour then the opportunity exists to have a pale blue
tint, perhaps as a background 'ghost' image. A range of greys is
also available from tints of black.
Two colour printing can be an economic way of
producing brochures and catalogues if full-colour images are not
required. There are creative options such as duotones which
can be considered if the subject matter is suitable.
Two Colour Machine
A press which prints two colours during one
pass through the machine. It is possible to print four
colour process by printing Cyan and Magenta,
changing the plates and then sending the sheets through again to
print the Yellow and Black.
UV Varnishing
A method of adding a gloss finish to printed
surfaces. The advantage of UV varnishing is that it is similar
to printing an extra colour and can be applied to selected areas
to produce special effects. The UV refers to the Ultra-Violet lamp
under which the varnished sheets pass for rapid drying.
Web
Nothing to do with the internet. A web printing
machine is one that accepts the paper on a large roll (the web).
These are very fast presses and are only economic for long run
and high volume work. Most people have seen film of newspapers
being printed — this is a web process. The majority
of magazines you find in the newsagent have been printed by web.
The opposite of sheet
fed.
Work &
Turn
When a whole job is printed on one side of sheet,
the sheets turned and printed again using the same plates. For
example, a single sheet A4 flyer is
printed with back and front adjacent to each other on one side
of an SRA3 sheet. The sheets are flipped
over and printed with the same plates again. When trimmed you have
A4 sheets with a different image front and back. The advantage
of this technique is to save a plate change
and make-ready cost. You may also hear the expression Work
& Tumble which is so similar as to only concern the pedantic.
Wove Paper
Uncoated paper often used for business stationery
which has no obvious surface texture or pattern. Compare to Laid
Paper.
|
