1. Material Properties – Paper & Boards
LESSON 3/5
Material Properties – Paper & Boards
Within this lesson you will cover:
Develop an understanding of the different printing methods which can be applied to both paper and boards (within school and industry).
Develop an awareness of their suitability for specific products and scales of production.

2. In a pairs, discuss the benefits of printing to: The user The client
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
DO NOW ACTIVITY
In a pairs, discuss the benefits of printing to:
The user
The client
Be prepared to share with the class your discussion and answer.
WHAT DO YOU THINK?

3. Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRIOR KNOWLEDGE
HANDS UP, DON’T SHOUT OUT! Can you name a printing processes that you already have knowledge off.

4. Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Commercial printing processes are distinguished by the method of image transfer used.
Depending upon the process, the printed image is transferred to the paper either directly or indirectly:
Direct printing: Image transferred directly from the plate cylinder to the paper e.g. flexography, screen printing and letterpress printing processes
Indirect/ offset printing: Image is first transferred from the plate cylinder then to the paper e.g. offset lithography , which is most widely used commercial printing process

5. Screen Printing PRINTING PROCESSES
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Screen Printing
Screen printing is a widely used commercial printing process for producing many mass or large-batch produced graphics, such as posters or point-of-sale display stands. A stencil is used to block off areas of the screen with a non-permeable material. This stencil is a negative of the image to be printed so the open spaces are where the ink will appear. Screens and stencils are produced using photo-emulsion technique
Screen print video:

6. Flexography Printing PRINTING PROCESSES
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Flexography Printing
Flexography video:
Flexography is often used for printing on plastic, foil, film, cardboard or other materials used in the packaging industry. Printing machines using flexo technique are based on flexible plates made of photopolymer. Using laser or through UV exposure on to the plates, the film negative image that is required is then imprinted. A thin layer of ink is deposited on the cylinder. A spatula called Doctor blade cleans the excess ink from the anilox, leaving only the desired amount in anilox cells (fine dimples). Anilox rotates & comes in contact with the plate, receiving the amount of ink required to make the image transfer on the print media.
Each print unit prints a single process of colour:
C= cyan
M= magenta
Y=yellow
K=black

7. Offset Lithographic Printing
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Offset Lithographic Printing
Lithography works on the basis principle that oil & water don’t mix (repel each other). Modern high volume lithography is used to produce books, posters, newspapers, packaging & mass- produced items in one production run.
With some modern lithography printing machines the image is put onto the printing plate by shining UV light through a negative (similar to a photograph negative). The plate is coated with a chemical which allows the ink (made from oil) to attach to the image area.
Lithography machines can print on both sides of paper/card & they rely on four basic colours – CYMK
Lithography video:

8. Digital Printing PRINTING PROCESSES
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Digital Printing
Modern printing methods such as laser & ink-jet printing are known as digital printing. In digital printing, an image is sent directly to the printer using digital files. This eliminates the need for a printing plate, such as offset printing, which can save money & time.
Unlike offset printing, you don't have to deal with colour separations and plate- making when doing digital printing.
However, things like colour calibration and using printed colour guides can be important for obtaining the kind of results you want from colour digital printing. 
Digital printing video:
Digital printing/ toner video:

9. Advantages, disadvantages & Applications
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Advantages, disadvantages & Applications
Process
Advantages
Disadvantages
Applications
SCREEN PRINTING
FLEXOGRAPHY
OFFSET LITHOGRAPHY
DIGITAL PRINTING
Using the knowledge you have learnt during todays lesson complete the table worksheet.

10. Paper & Board Printing Processes.
Advantages, disadvantages & Applications
Process
Advantages
Disadvantages
Applications
SCREEN PRINTING
FLEXOGRAPHY
OFFSET LITHOGRAPHY
DIGITAL PRINTING
Worksheet to print for students

11. PRINTING PROCESSES Process Advantages Disadvantages Applications
Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
PRINTING PROCESSES
Process
Advantages
Disadvantages
Applications
SCREEN PRINTING
Stencils easy to produce using photo-emulsion technique
Versatile- print on any surface
Fully automatic methods capable of producing large volumes
Difficult to achieve fine detail
Print requires long drying time
Produced in smaller quantities like batch production
T-shirts, plastic and metal signage, point-of-sale displays, promotional items e.g. pens, glasses and mugs
FLEXOGRAPHY
High speed printing process
Fast-drying inks
Can print on same presses as letterpress
Colour may not be consistent
High set-up costs, rarely print runs below 500,000
Packaging, less-expensive magazines, paperbacks, newspapers
OFFSET LITHOGRAPHY
Good production quality, especially photographs
Inexpensive printing process
Print on wide range of papers
High printing speeds
Widely available
Colour variation due to water/ink mixture
Paper stretches due to dampening
High set-up costs makes it uneconomical on short runs
Only used on flat material
Needs good quality surface
Business stationary, brochures, posters, magazines, newspapers
PRINTING
DIGITAL
Less expensive and less time-consuming for producing short runs
Eliminates the expense of plate-making and setting up the presses.
Easier and less expensive to make last-minute changes to a print job
File preparation can be less complicated for those unfamiliar with commercial printing methods
Slightly less quality than offset printing
Graphics file-type problems, colour, compression, complexity, and missing images will jeopardise the digital printing job
Inks fade quickly when exposed to sunlight
Book publishing, brochure printing, poster printing, business card printing, full colour printing, postcard printing, calendar printing, photo printing
Answers

12. Objective - Learner will gain knowledge and understanding of different printing methods which can be applied to both paper & boards
HOMEWORK
A two colour design will be added to a concert ticket using screen printing process. Explain two reasons why screen printing is a suitable method for batch production (4marks)
The graphics on some cans are applied using flexography printing process. Using annotated sketches, describe the flexography process. (5marks)
Figure 1 shows a diagram of the offset lithographic printing process Figure 1
(i) Complete the diagram by labelling each of the indicated parts of the offset lithographic printing process (5marks)
(ii) On the diagram indicate the direction of rotation of cylinder X. (1mark)

13. A two colour design will be added to a concert ticket using screen printing process. Explain two reasons why screen printing is a suitable method for batch production (4marks)
The graphics on some cans are applied using flexography printing process. Using annotated sketches, describe the flexography process. (5marks)
Figure 1 shows a diagram of the offset lithographic printing process Figure 1
(i) Complete the diagram by labelling each of the indicated parts of the offset lithographic printing process (5marks)
(ii) On the diagram indicate the direction of rotation of cylinder X. (1mark)
Homework sheet to print – students to answer on lined paper