Remove any dirt and oil from the mesh screen by applying a thin coat of degreaser (any commercial kitchen cleaner will suffice) to the front and back. Wipe off with a soft cloth.
Move to a dimly lit room. Saturate a foam paintbrush with emulsion and apply a smooth, uniform coat to each side of the screen. Face a small fan toward the frame and allow it to dry for an hour or two.
Place the film positive onto the front of the screen. An ideal film positive is a stark clear design printed on a clear transparency sheet, although stencils are often used. The resulting image burned onto the screen will be the film negative.
Set a clear glass panel over the artwork. This holds the artwork securely in place while the image is being burnt, producing maximum clarity and detail in the film negative.
Lay out a black cloth or towel in an open, sunny area. Place the screen on the towel and allow it to be exposed to the sun for 10 to 20 minutes.
Rinse the screen out using a garden hose with adequate pressure. This washes away the burnt emulsion and finalizes the film negative. The screen is now ready to be used for printing.