STEP 1
Open your portrait image, hold down the Alt/Opt key, drag the original image layer to the “Create a new layer” icon, call the new layer “Cut Away,” and click OK. Use selection tools such as the Magic Wand and Color Range to roughly select and delete the background pixels from the new layer.
Silkscreen images are very high-contrast, and later steps will remove much fine detail, so you don’t need to be very precise. It can make it easier to work if you add a new, color-filled layer directly below the working layer—making it a garish color can help you see the final result.
STEP 2
To make the high-contrast image, ensure the Cut Away layer is active and select Image > Adjustment > Threshold. Move the slider so that the image contains only enough shadow to show the picture’s essential shapes.
STEP 3
Roughly select each image area that you want to paint with a single color, and use Alt/Opt + Ctrl/Cmd + J to copy the selection into its own layer. Name each new layer, set the blending mode to Multiply, and click OK.
STEP 4
Activate each item’s layer in the Layers palette in turn. For each one, Ctrl/Cmd + click the thumbnail so that only its non-transparent pixels are selected, and choose Edit > Fill. Even if the Fill dialog’s Use drop-down shows Color, select it again. This triggers the Color Picker. Select a strong color and click OK twice.
STEP 5
In the Layer Style dialog box, change the Color Overlay’s blending mode to Color. Pick a strong color and click OK.
STEP 6
Once you have repeated steps 4 and 5 for each colored item, you have a completed silkscreen-style image. Save the file and make copies in which you use permutations of the same colors. Each colored area is in its own layer, so it is easy to select and recolor it with a Hue/Saturation adjustment layer. Finally, combine all the versions in one large image.
Combining multiple versions of the same image lends the final version a distinctive 1960s Pop Art feel.