Chapter 23 Screen Printing
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
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
Applications Posters, plastic bottles, drinking glasses, soda bottles, mirrors, metal surfaces, wood, textiles, printed circuit boards, product displays, vinyl binders, etc
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
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
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
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
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
Screen Preparation
Screen Exposure
One Color Printing Process
Screen Clean Up
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?