GCSE Graphic ProductsGCSE Graphic ProductsPrinting and Print finishesPrinting and Print finishes

Summer Examination 2011

PrintingPrinting

How the printing process works: The three stages of printing.1. Pre-press – the stages needed before actual printing takes place.2. Print – the stages of printing the design.3. Finishing – any additional processes that may be needed.

Pre-press:Checking artwork – the artwork is checked to make sure a suitable print process is chosen. The printer will look at font types, colours, quality of pictures etc.

Colour Separation – this is the process through which the original images are broken down and separated into the four process colours used by a computer program. (CMYK: Cyan, Magenta, Yellow, Black, ‘K’ represents the ‘key’ colour)

Print quality – the printer knows that each of these colours will be printed on top of each other. It will check the resolution of the image and print accordingly.

PrintingPrinting

Printers and customers always want the highest quality they can achieve for their images. To achieve this quality the printer can place imagery on the outsides of the printed image to check different aspects of the print quality.

Registration marks: a very clear mark about 10mm across of a circle and lines. This is used to check the printing plates are aligned.

Colour bar: a small strip of the process colours (CMYK) printed outside the actual image. It is used to check the density of the four colours.

Crop marks: these are found at the four corners of the page. They tell the printer where to crop of guillotine a printed image.

Printing ProcessPrinting Process

The Printing process – Step by Step

Stage 1 – Artwork is scanned into a computer and sent to printer via email or a CD/USB

Stage 2 – Printer colour separates image into CMYKStage 3 – Printer adds registration marks and colour bar for quality control

checks. Adds crop marks for where to guillotine the print. Stage 4 – Printer makes 4 printing plates, one for each colour.Stage 5 – Plates are carefully aligned on machine, normally around a cylinder.

Stage 6 – Job is printed with regular quality control checks on plate alignment and colour density.

Stage 7 – Any special printing effects are added, for example varnishing, laminating, embossing.

Stage 8 – Print is guillotined to size.Stage 9 – Print is packaged and sent to a distribution center from where it will

then go to the shop to be sold.

Pre-Press

Print

Finishing

Print ProcessesPrint Processes

Process Common use Advantages Disadvantages Cost (10=High) Quality (10=High)

Offset Lithography

Newspapers, Magazines, Books

Most common method, high quality, fast,

prints well on paper.

Expensive set up cost

5 9

Flexography Packaging, Corrugated boxes, Shopping bags, 3D

surfaces

Fast Expensive set up cost

6 8

Screen Printing

T-Shirts, Large posters, Short

print runs

Good for short print runs, can

print on absorbent surfaces.

Not as good a quality, can be

slow.

4 6

Gravure Expensive, High Quality

magazines, Stamps

Best quality printing, very fast process

Very expensive set up cost

8 10

Laser One-Off items Immediate printing, no set

up cost.

Very expensive for individual

prints

10 7

Printing processPrinting process

Offset Lithography: Plates and PaperOffset lithography is used for about 70% of printing, it is always nearly used for printing onto paper and thin card. The ‘offset’ means that the actual printing plate never touches the paper because the image is first transferred, or offset onto another cylinder.

1. The printing plate has the image to be printed, in relief, on its surface (the image stands out slightly from the printing plate surface).

2. The printing plate is kept dampened. Ink is applied to the plate but it is repelled from the dampened surfaces which are the non-image areas.

3. As the printing cylinder rotates the ink is transferred to the rubber blanket cylinder.

4. The ink, now on the rubber blanket cylinder, is pressed onto the paper or card as it is pulled through the machine. (The paper is trapped between the blanket cylinder and the impression cylinder - these pull the paper through the machine)

Printing processPrinting process

FlexographyThe process for Flexography is very similar to Lithography, using the four process colours, but as the name implies, the printing plate is made out of flexible rubber. The image sticks out slightly, unlike lithography where the image is totally flat.This makes it a better process for printing onto something that has an uneven surface such as card, plastic or metal. The printing plates can last twice as long as lithography plates also.

Digital Printing This is just like printing to the printers in classrooms, you will be most familiar with this method of printing.It is good for printing small jobs, on an inkjet or alaser printer. Industry will use this type of printing for batch jobs of up to 3000 prints. The printing plates do not need to be made, the process colours CMYK, are used, and you can still achieve a high print quality, but this means the print costs can be higher.

Printing processPrinting process

GravureGravure is the most expensive to set up, printing process. Like flexography, the image sticks out from the background, but the plate is made from brass this time. It is used for full colour magazines, stamps, and special high quality reproductions of photos. The plates can be very expensive to make and so the print jobs are usually around the 1,000,000 marks.

Screen PrintingThe screen printing process is different to the others we have looked at. It allows you to print onto a vast amount of surfaces such as T-shirts and Point of Sale Stands.It is useful for short print runs, as it is cheaper to set up. Images are made into a stencil through which the ink is Forced onto the product. The image is put onto a very fine mesh or gauze. The quality is not always as good however.

Print finishesPrint finishes

Why do we use print finishes?Different special effects that are used when printing can help to sell the product. By using print finishes, you can create special effects, which could enhance an image, but these are often expensive to use, as they require separate machines to printing processes.

Aesthetics: helps the products look betterProtection: helps to protect from wear and tear.

There are 5 types of printing finishesVarnishingFoil blockingLaminatingEmbossingDie cutting

Print FinishesPrint Finishes

VarnishingThis is similar to adding a coat of varnish to wood. The process used to be a slow process of adding a coat of oil based varnish to a printed product, but technology now has advanced the process to make it quicker and can even add UV (Ultraviolet) varnishing to give a better effect. When passed under a UV light the varnish will dry quicker and set immediately. Spot Varnishing is where only a certain part of he printed surface is highlighted by the varnish. This adds to the image quality and has a greater graphical impact.

Foil BlockingThis is a great process for making a product look more expensive. It works by stamping a pre glued metallic foil onto the printed surface by using heat and pressure. It is used a lot on cards and expensive packaging.

Print FinishesPrint Finishes

LaminatingSome products need to be laminated, which provides greater protection than a simple layer of varnish. The lamination process involves heat, sealing a layer of a clear polymer such as PET, (Polyethylene terephthalate) to the surface using heat and pressure from a big steel roller. Laminating can improve the strength of a page to improve the appearance, and produce a ‘wipe-off surface’.

EmbossingEmbossing raises part of the surface by applying about 5 tonnes of pressure to a steel die or stamp onto the printed surface. This usually gives a visual effect that can be subtle also. It can increase the cost of printing due to the et up costs.

Practice QuestionsPractice Questions

This question is about commercial printing and scales of production.

1. Name the four processing colours, in the order they are usually printed.

2 (a) Name five methods of commercial printing.2 (b) Which method is usually associated with printing the following:

◦ Plastic bags◦ Stamps◦ Fabrics◦ Newspapers◦ Bottles◦ High quality one off items.

This question is about Print Finishes.

3. Describe each of the following, and explain how it can enhance a product. UV Varnishing, Embossing, Foil Blocking, Laminating, Spot Varnishing.