A quick photographic guide to using Diazo Photo Emulsion (Speedball or Jacquard) with a simple home set up.
To start you need a grease-free, clean, dry screen. You can use Speedball Speedclean, Screen Cleaner or even washing up liquid. Wash and rinse your screen well and then leave to dry. To coat your screen you will need photo emulsion, scoop coater, cold water and a spoon.
Following the instructions on the bottle, fill the sensitiser half full with cold water and mix well. The handle of the spoon is useful to ensure that you have reached all the sensitiser from the corners. Once you have dissolved all of the sensitiser pour the contents into the Photo Emulsion and stir well.
Pour some photo emulsion into the scoop coater and allow it to settle. Press the edge of the scoop coater firmly against your screen and tilt until the flat edge of the scoop coater is touching the screen. Drag the scoop coater smoothly up the screen to ensure an even coating, when you reach the top, tilt the scoop coater back so the emulsion falls back into the scoop coater. Repeat on the inside. If the emulsion is uneven use the scoop coater tilted back to remove any excess.
Place the coated screen horizontally somewhere dark to dry. The air needs to circulate around the screen so rest the edges of the frame on blocks or coins. When it is completely dry it is ready to expose. Place a piece of black foam or a book covered with a sheet of black paper under your screen. Position the film positive so the image is backwards if your light is coming from above and then sandwich this together with a sheet of glass. Turn on your lamp and expose. We expose for 15 minutes with our 250W lamp, if your lamp is a higher wattage the exposure time will be shorter.
When the screen has exposed you will be able to see a difference in the colour of the emulsion. The unexposed emulsion looks a little more yellow. Wet both sides of your screen and then use a powerful jet of water (a shower hose, garden hose or pressure washer is good) to spray off the unexposed emulsion and reveal your image. Leave your screen to dry before you print.
You can download a printable pdf here.