Screenprinting the Easy Way

Screenprinting is a process that utilizes the properties of a stencil; some areas are blocked out and other areas are printed through.

Open the image, duplicate layer (as always), crop image, remove background

Original image

Make a "stencil" the easy way:

Select Image>Adjustments>Threshold



"Stencil"

Colour the background:

Add a New Fill Layer>Solid Colour—Yellow, Blend Mode: Multiply

Yellow

• Flatten the layer
• Copy to a new file with a width and height of 3 times the original
• Return to the original and undo flattening
• Change the colour of the Fill Layer to blue
• Repeat steps for all the other colours

Here is a description of the method Andy Warhol may have used to create stencils for his screenprints. It sounds a lot more complicated to me.

"The stencil is created on a mesh screen using a light sensitive emulsion which hardens when exposed to light. First the screen is coated with the light sensitive emulsion. Next a black and white photograph is photocopied onto a transparent overlay. The transparent overlay is placed underneath the screen, which is placed on top of a light box. The screen is exposed to light, hardening the emulsion everywhere except where the image overlay has been placed. The area of the screen not exposed to light does not harden and can be washed away to reveal a stencil of the original image."
http://www.christies.com/features/andy-warhol-and-the-art-of-screenprinting-2752-1.aspx