Photoshop Scan Lines: Create and Define Patterns

Back in the day (oh, about five years ago), the Photoshop "scan lines" effect was all the rage. It was overused, but with good reason: it's a really cool effect (see Image 1). Adding the scan lines effect to an image makes it appear as if were captured off a TV screen. With this step-by-step Photoshop tutorial, you will learn to create scan lines quickly and easily.

Topics covered in the tutorial:
Photoshop's Define Pattern feature
using the pencil tool
creating a new layer and filling the new layer with a pattern
using layer blending modes and opacity to fine tune the effect

First, we will create the scan lines pattern in Photoshop. Then we will open up the photo we're using and apply the pattern to it.

Creating the scan lines pattern

Create a new image
Usually in these tutorials, we open an existing photo and begin working on it. This time, however, we'll start with a new image. Click the File menu and scroll to New... or type cmd-n (ctrl-n on Windows). Make a new file 1 pixel wide by 4 pixels high, and choose "Transparent" for the Background Contents. The new file probably looks very tiny. Under the View menu, select "Zoom In" or type cmd-plus sign (ctrl-plus sign) and zoom in to 1600%.

Create the scan lines pattern
Type the letter "D" to reset the foreground and background colors to default. Select the Pencil tool in the Tools palette (click and hold on the brush tool to select it [Image 2]). Using the Pencil tool, fill the top half of your image with black. This will take just two clicks, one at the top and one just below that.

Save the scan lines pattern
Click the Edit menu, and scroll down to Define Pattern.... Name your pattern "Scan Lines." It may seem obvious right now, but it bears spelling out: giving your patterns a memorable, pertinent name is a Very Good Idea.

Applying the scan lines pattern to your photo

Open your photo
Open the photo you want to add scan lines to in Photoshop. You can use Image 3 from this tutorial, if you wish. Click the New Layer icon in the Layers palette.

Fill the new layer with the scan lines pattern
Click the Edit menu, and scroll down to Fill.... Under "Contents" click the dropdown menu and select Pattern. Click the Custom Pattern dropdown menu and select the scan lines pattern you just created. Under "Blending" leave mode to Normal and Opacity at 100%. Click OK.

Adjust the scan lines to your taste
You now have a very dark set of scan lines in a layer atop your image (Image 4). The final step is to apply a layer blending mode and adjust the opacity of the scan lines. In the Layers palette, select Overlay from the dropdown menu. Note: Soft Light also adds an interesting dimension.

The effect probably still looks a bit dark, so move the Opacity slider in the Layers palette down to 50% or so. You can adjust the opacity to make the scan lines as strong or subtle as you wish. Image 1 is set to Overlay at 50% opacity.

And that's it! By using a few clicks of the pencil, Photoshop's Define Pattern feature, and tweaking some layer blending modes, you've added the TV scan lines effect to a photo.