You don’t need to use a cartoonish image as I have done in this post, for this example. Any image will do; it can be a realistic image. I worked on the following image at 72 ppi (pixels per inch, RGB mode).
You will need to have whatever image you want to use cut out from the background for this to work.
The end result should look something like this shark image below – a halftone pattern around or behind the shape:
Place your image (in my case, a shark drawing – and it’s the shark only, there is no background to the shark) on to its own layer.
Use Load Selection on your image, create a new layer, and while on that new layer, fill the Selected area on the new layer with Black – with the selection still “on” (do not de-select at this point), go to Select > Modify > Expand on Photoshop’s menu.
Once there, choose 10 (ten) as the amount to Expand and click OK.
Select Black as your Foreground color (which you can do by pressing “d”) and fill the selection with Black.
While this shape is still selected, duplicate the layer by dragging it on to the New Layer icon on the bottom of the Layers palette.
Next, press the letter “Q” to enter into Quick Mask mode. (At this point, your layer will fill with Red, or whatever color you have chosen for your mask color – for me, that would be Blue, as you can see in this screen capture below)
Choose Pixelate from Filter on Photoshop’s menu and choose Color Halftone.
You can use the default settings and click OK.
You may need to apply this filter several times in a row (which you can do via Command-F (or on the PC: Control-F).
Press the letter “Q” to leave Quick Mask mode, which results in a selection on your layer. Fill this selection with black (on the PC: ALT-Backspace, Mac: Option-Delete).
De-select the selection. Slightly blur the black shape on Layer 2 by using Gaussian blur at 5 or 6 pixels (or whatever amount looks good to you).
Place your image layer (in my example, it would be the Shark image) on the very top of all the other layers, so that it sits above the black blurred shape and black Halftone Dot pattern shape.
Of course, you don’t have to set your background color to light blue (as in my shark example) or in white – you can use any color you like.
You also don’t have to stick with black as your Halftone color. Once you have created the half tone color, and as it’s on its own layer, you can load it as a selection, create a new layer, and fill the Halftone pattern selection with whatever color you wish.
Here is an example where I filled the Halftone Pattern area (originally in black) with a light blue, and switched the background from a light blue to a dark blue:
(I sometimes use this Halftone Pattern technique in projects, one that I once saw in a book, but I am always misplacing the book and even forgetting which book I saw it in, so I’d like to make a blog post about this to have this information in one place that I can easily reference.)