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SCREEN PRINTING (download PDF 1.0MB)
Introduction Preparing the Stencil & Emulsion Printing
Screen Print Materials Exposing the Stencil Stencil Removal / Screen Reclaiming
G&S Pigment System Paints Exposing Units / Methods Trouble Shooting
Creating Artwork Preparing for Printing Iron On Transfers
Mesh / Screen Preparation Printers Equipment Prices

EXPOSING UNITS

TABLE TOP EXPOSING UNIT

Ideal for schools or small shops! All the features of the larger unit But compact and economical.

Features:

  • High quality live rubber vacuum blanket
  • Dimensions: glass surface 27" x 31"
  • Powerful vacuum pump to ensure tight contact between screen and positive for perfect screen stencil making.
  • High efficiency, ultra-violet light tubes for perfect exposure.

BUILDING AN EXPOSING UNIT:

Two types of simple exposing units may be built with materials you already have on hand, or can easily purchase. One uses fluorescent tubes, the other a 150 watt plant light. These are inferior, but may be sufficient for the task on hand.

A) THE FLUORESCENT TUBE UNIT

You will need four double fluorescent fixtures (2 or 4 feet long), and enclose them in a wooden or metal box. Place a sheet of 1/4"/6mm glass over the top, leaving two inches between the bulbs and the glass.
glass
fluorescent tubes
TO EXPOSE:
  1. Place the screen underside or print side down on the glass of the exposing unit.
  2. Weigh the screen down with a cloth-covered piece of plywood, cut slightly smaller than the inside of the screen (or use a book). Place two bricks or weights on top to ensure proper contact. It is essential that contact be as tight as possible, or the result may be loss of fine detail, as well as make washing out more difficult.
  3. With the fluorescent tube we recommend an exposing time of five minutes as a first test.

bricks
plywood
screen
film
exposing unit

THE PLATE LIGHT

A very effective and economical way to expose a screen using a regular 150 watt plant bulb. This avoids the costly investment of a vacuum exposing unit or building a complex light table. This method is ideal for screens that are less than 20Óx24Ó OD.

ceiling mounted
desk mounted

TO EXPOSE

  1. Tape the film positive to the screen side (outside).
  2. Place the styrofoam block on squeegee side (inside).
  3. Position the screen with the foam on a table, positive side up and place the sheet of glass on top of the screen. This secures the film and ensures proper contact with the screen.
  4. Expose for 25 minutes at 12-15Ó distance from the screen.
  5. Immediately after the screen is exposed, remove the positive and spray the print side of the emulsion with water until the unexposed areas are completely clear.
  6. Blot with unprinted newsprint and dry horizontally.
  7. Once fully dry, place screen against a window or in front of a light source and check stencil for pinholes. Using a small brush, patch up with unused emulsion.
  8. Once emulsion is dry, the screen is ready to use.

EXPOSURE TIMES OF DIFFERENT STENCIL MATERIALS

The following times are approximated for use with the Exposing Unit (UV Black Light)

Capillex Films

Capillex 25 4.5 min
Capillex 35 5.0 min
Capillex 50 5.25 min
Capillex XR40 6.0 min
Capillex XR80 8.0 min

 

Velum

Generally add 20% to exposure times

DIRECT EMULSIONS

Duracoat 74-86 mesh 4.0 min
  110-160 mesh 3.25 min
  200-230 mesh 1 min
  255-305 mesh 50 sec.
Autosol Fast 74-86 mesh 4.0 min.
  110-160 mesh 3.33 min.
  200-230 mesh 2.5 min
  255-305 mesh 2.0 min