what do we need to know for our exam l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
What do we need to know for our exam???? PowerPoint Presentation
Download Presentation
What do we need to know for our exam????

Loading in 2 Seconds...

play fullscreen
1 / 16

What do we need to know for our exam???? - PowerPoint PPT Presentation


  • 151 Views
  • Uploaded on

The AQA (our examining board) specifies the following: Quality checks such as colour registration marks, position marks. Commercial printing methods- letterpress, lithography, flexography, gravure and screen printing. Varnishing (oil, spirit, UV and water).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'What do we need to know for our exam????' - Faraday


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
what do we need to know for our exam

The AQA (our examining board) specifies the following:

Quality checks such as colour registration marks, position marks.

Commercial printing methods- letterpress, lithography, flexography, gravure and screen printing.

Varnishing (oil, spirit, UV and water).

Laminating, embossing and foil application.

Multiple surface developments (nets) produced by die cutters and creasing bars.

What do we need to know for our exam????

Modern Printing Methods explained.

GCSE Graphic Products

the five main types of printing are
Relief- Letterpress, Block printing, Flexography (foil blocking)

Planographic (flat plate printing)- Lithography & offset lithography

Intaglio (etching) – Gravure, Screen Printing

Xenography (dry printing)- Photocopying, Laser printing, commercial digital printing

Please note that while it is good to know what these are, not all are required for the AQA syllabus.

The five main types of printing are:

Modern Printing Methods explained.

GCSE Graphic Products

flexography

Flexography is a form of relief (a raised profile) printing.

The image is slightly raised, inked and the printed straight onto the substrate (technical term for paper, card or whatever is being printed on).

The plate is usually made from soft rubber or plastic and uses a quick drying ink.

This high speed process is well suited to a number of materials such as acetate film, polyethylene (eg supermarket bags), brown paper and newsprint.

For more information visit: http://graphics.tech.uh.edu/MatProcesses/Flexography.html

Flexography

Flexograph machine

a rubber flexograph plate

Modern Printing Methods explained.

GCSE Graphic Products

offset lithography
Offset Lithography is by far the most common form of commercial printing. It accounts for over 70 % of commercial printing.

Offset lithography works on a very simple principle: oil and water don’t mix. Images (words and art) are put on plates which are damped first by water the by oil-based ink. The ink sticks to the image area , the water to the non-image area which absorb moisture and repel ink. Then the image is transferred to a rubber roller and then to the substrate. This happens at an extremely fast speed as the plates are wrapped around a roller. The paper is web fed (a continuous roll).

Offset Lithography

Modern Printing Methods explained.

GCSE Graphic Products

what happens inside
What happens inside…

An offset lithography machine has four of these presses, printing the cyan, magenta, yellow and black (CYMK) components of a print.

Modern Printing Methods explained.

GCSE Graphic Products

slide6
Advantages of offset lithography:
  • Prints 4 colours onto flat materials
  • It is a high quality process
  • Very economical on medium to large production runs 500 - 500,000
  • It is a fast process – speeds of up to 50,000 presses per hour can be acheived on a web – fed press!
  • Disadvantages of offset lithography
  • Less economic than rotogravure and flexography on high volume printing 1,000,000+
  • Less economic than digital printing on small to medium runs 50 -100,000(although quality is slightly higher)
  • Limited to the type of materials it can print onto – the surface must be flat. Litho would not be accurate enough for newspaper print.

Modern Printing Methods explained.

GCSE Graphic Products

gravure
Gravure

Gravure is a printing process that uses intaglio or engraved metal plates or cylinders. The image to be printed is photo-etched onto the plate as microscopic dots. Rotogravure is a printing technique characterised by high print quality and large numbers of copies – hundreds of thousands or even many millions. Tiny ink volumes are transferred from the gravure printing cylinder to printing dots on the paper. Millions of printing dots show up to the human eye as letters/text or images

The "doctor blade" is angled against the cylinder to wipe away the excess ink, leaving ink only in the cell wells

Modern Printing Methods explained.

GCSE Graphic Products

slide8
The main application of gravure covers a wide range of commercial products.

Gravure is especially suited to work in the four colour process on relatively

cheap papers in quantities over 250,000. The reason being the expense of the

original printing plates which can each run into thousands of pounds.

Example applications include

magazines

mail-order

catalogues

Board packaging products such as folding box cartons for food and cigarette industries, also printed video cases.

Flexible packaging such as printed cellophane and polythene used in food wrapping, display and production.

Modern Printing Methods explained.

GCSE Graphic Products

slide9
Advantages of Gravure:
  • It can be used for the highest quality reproductions
  • It uses lower grade, lighter paper than lithography
  • High speed usually 6000-10,000 prints per hour
  • Automatic registration.
  • Disadvantages of gravure
  • Initial cost of rotogravure plates extremely high therefore it is only economic for very high print runs
  • Colour correction is difficult

Modern Printing Methods explained.

GCSE Graphic Products

silk screen printing
Silk Screen Printing
  • Screen Printing is unlike any other process as it uses a stencil through which ink is
  • pushed. The process involves forcing ink through a fine mesh (screen) which helps to
  • spread the ink evenly.
  • Its easy to use, versatile and requires low capital investment.
  • Relatively cheap – on short and medium print runs – automated presses which can print, varnish or gum up to 6000 per hour.
  • Most importantly it can print onto curvrd and uneven surfaces

Modern Printing Methods explained.

GCSE Graphic Products

the main stages of modern print production

origination

compostion

Prepress

Colour separation

Plate production

sheet or web fed

print

4 colour printing

Quality control

The main stages of modern print production

Stiching binding stapling

Embossing, blocking

Finishing

Varnish and laquer

Die cutting and creasing

Modern Printing Methods explained.

GCSE Graphic Products

the main stages of modern print production12
The main stages of modern print production
  • The basic stages of modern print production are:
  • Original artwork – photographs, illustrations and text – are scanned and entered into a computer
  • These elements are combined into a document using page makeup or desktop publishing software
  • Full size films are output using a high-resolution imagesetter. These could be either positives or negatives.
  • Printing plates are made from films using a photochemical process
  • The flexible plates are attached to the plate cylinders of a litho press and the job is printed.

Modern Printing Methods explained.

GCSE Graphic Products

full colour printing
Full Colour Printing
  • For printing, and image is separated into its
  • colours Cyan, Magenta, Yellow and Black
  • (CMYK).
  • Each colour is printed over the other as the
  • paper (or substrate) moves through the
  • presses. Each colour has its own press.

Cyan

magenta

yellow

black

For the original go tomicro.magnet.fsu.edu/.../primarycolors/ colorseparation/

Modern Printing Methods explained.

GCSE Graphic Products

quality control

Registration marks at about 10X magnification

Quality Control
  • The two main quality checks are:
  • Registration
  • Colour Density
  • Registration can be checked by either eye or automatically and are used to check that the 4 processes are aligned properly on the substrate. Images out of alignment can appear blurred.
  • Colour density is checked using a Densitometer, which is a hand held device that measures the density of colour.
  • The densitometer is held over the colour bar (one colour for each of the process colours and greyscale.

A colour density bar

Modern Printing Methods explained.

GCSE Graphic Products

binding
Binding
  • Once printed the next stage is the binding of the product. The bindery is where the
  • printed product is completed. The huge rolls of now-printed paper are cut and put
  • together so that pages fall in the correct order. Pages are also bound together by,
  • staples or glue, in this step of the process.
  • A machine called a stitcher takes the folded printed paper (called press signatures)
  • and collates them together.
  • The final components in the stitcher machine are the knives which trim the paper to its final delivered size.

A sticher machine

Paper being cropped manually

Modern Printing Methods explained.

GCSE Graphic Products

cutting and folding creasing
Cutting and Folding (creasing)
  • Most cartons (packages, boxes) require cut outs and creases in order for them to be
  • assembled. The machine tool used on modern presses is the die cutter.

Modern Printing Methods explained.

GCSE Graphic Products