Screen Printing

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Screen Printing
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The process of forcing ink through a porous
fabric and the open areas of a stencil to produce
an image.
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Two terms commonly used Serigraphy (in the field
of fine arts) and Screen Printing used in the
graphic communications industry.
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Applications for Screen Printing

• Posters
• Plastic bottles
• Drinking glasses
• Soda bottles
• Mirrors, metal surfaces
• Wood
• Textiles
• Printed circuit boards
• Product displays
• Vinyl binders

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Advantages of Screen Printing

• Images can be printed on a wide variety of
  substrates
• The production process is relatively easy.
• Capital expenditures are low compared to other
  printing processes
• Images can be printed with glitter, flock, and
  other decorative finishes.
• The ink film is very resilient due to the extreme
  thickness of the ink deposit

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Disadvantages of Screen Printing

• The process is usually limited to flat,
  relatively thin substrates, such as paper, metal,
  or plastic.
• Rate of production is slow.
• Ink mileage is poor.
• Excessive drying times may be necessary.
• Details and fine line images may be difficult to
  print.

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Basic Equipment for Screen Printing

• Screen fabric
• Frame
• Stencil
• Ink
• Squeegee
• Substrate

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Squeegee blades

• Square edged flat surfaces and general purpose
  printing
• Square-edge with round corners Gives extra-heavy
  ink deposits on flat substrates. Used when a
  light color will be printed on a dark substrate.
• Round-edge Used primarily in textile printing
  where an extra-heavy ink film is required.
• Single-sided beveled edge Used for printing on
  glass.

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Squeegee Blade Shapes (cont.)

• Double-sided beveled edge with flat point. Used
  for printing on ceramics
• Double-sided beveled edge. Used for printing on
  cylindrical objects such as bottles and
  containers.

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Squeegee Blade Shapes
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Screen Inks

• Water Based
• Oil Based

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Screen Printing Solvents

• Water
• Mineral Spirits (or mineral spirits substitute)

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Screen Frames

• Wood
• Aluminum
• Steel
• Plastic

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Screen Fabrics

• Filaments are threads
• Multifilament sewing thread example
• Monofilament fishing line example
• Mesh count number of threads per linear inch
• The higher the mesh count, the better the
  reproduction of fine details.

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Mesh Count (cont.)

• Multifilament ranges from 5 to 25. Multiply the
  digit by 10 to get an approximate number of
  threads per linear inch.
• Monofilament are specified by actual number of
  threads per linear inch.

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Fabric Strength

• X
• XX
• XXX
• Most screen printers select XX multifilament or
• T- monofilament.

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Types of Fabric

• Silk - most expensive
• Organdy - cheapest
• Polyester - middle of the road
• Nylon - used for non-flat substrates
• Metal Mesh - most durable, but expensive
• Metalized Polyester - durable but not too
  expensive

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Fabric Attaching and Tensioning

• Stapling
• Cord and Groove
• Mechanical Clamping
• Adhesive Bonding
• Measuring Fabric Tension - tensiometer
• Fabric Treatment - abrading

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Stencils

• Knife-cut stencils Paper stencils,
  water-soluble stencils,lacquer-soluble stencils
• Photographic Stencils indirect, direct,
  direct/indirect

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Screen Printing at Pope

• Aluminum Roller Frames
• XX, monofilament, polyester mesh
• Photographic direct emulsion
• Plastisol (oil based) ink
• Mineral spirits substitute
• Emulsion removed and screen cleaned with special
  solvents and water.