1. Chapter 23
Screen Printing

2. Screen Printing
The process of forcing ink through a porous fabric (screen) and the open areas of a stencil to produce an image
Serigraphy, mitograph, silk screen, stencil printing, screen process
Serigraphy- fine arts
Screen Printing- graphic communications

3. Screen Printing Few inexpensive tools and materials
Simple Process
Few inexpensive tools and materials
Complex Process
Array of sophisticated equipment and production techniques
Complexity
Level of quality required in finished piece

4. Applications
Posters, plastic bottles, drinking glasses, soda bottles, mirrors, metal surfaces, wood, textiles, printed circuit boards, product displays, vinyl binders, etc

5. Versatile Process
Advantages: wide variety of substrates, easy production process, low capital expenditures, decorative finishes, resilient ink film
Disadvantages: process is limited to flat, thin substrates, slow rate of production, poor ink mileage, excessive drying times, difficult to print details and fine line images

6. Screen Printing Process
Equipment: screen fabric, frame, stencil, ink, squeegee, substrate
Porous fabric is stretched across frame
Stencil is adhered to fabric blocking out portions and leaving open the desired image area

7. Ink is poured onto fabric and forced through image area using a squeegee
Ink is deposited on substrate, producing image of cut stencil
Multiple prints are created by repeating the process on new substrates

8. Photographic Stencils
Light sensitive
Exposed using a positive film image
Right-reading on emulsion side
Indirect: exposed off the screen fabric
Direct: exposed after a light-sensitive emulsion has been applied to screen frame
Direct-Indirect: combination of the two stencil techniques and materials

9. Diazo Emulsion Used with water-based or solvent-soluble inks
Applied with scoop coater to both sides of screen
Substrate side of emulsion should be smooth
Exposure is made with a deep-bottom vacuum frame
Positive is positioned on substrate side and should be in contact with screen emulsion
Exposure to light causes areas to harden and become insoluble in water
Unexposed area will be washed away
Blockout can be applied to fill in pinholes and other uncoated areas
Emulsion is removed using a reclaiming solution

10. Screen Preparation

11. Screen Exposure

12. One Color Printing Process

13. Screen Clean Up

14. Review Questions
What are some typical applications of screen printing?
What are some advantages of screen printing?
What are some disadvantages of screen printing?
Describe the basic screen printing process.
When using a Diazo emulsion, how should the positive be positioned?