Diagonal scanlines

Create a new image ( File > New or Ctrl+N ) with this settings:
Width: 3 pixels
Height: 3 pixels
Background: Transparent

Now take the Pencil tool (Right click on the brush tool and select Pencil) and take a 1px brush and black color. Make this with the pencil tool (Image is zoomed):

Go to Edit > Define pattern and this will appear:

Put whatever you want for the name and click OK. Now open the image you want to apply the diagonal scanlines ( File > Open ) and make a new layer. Name it Pattern, for example:

We're going to apply the pattern. To do this, go to Image > Fill and select Pattern from the dropdown, then select the pattern we did before:

This is more or less what you'll get:

Making the lines softer

We're going to change the layer Blending mode. At the Layers window change the blending mode to Overlay.
You can also try the other ones to see which one you like most!

Here's my final result!

NOTE: If you want more space between the lines you just have to create a bigger image when doing the pattern (for example, 4 pixels instead of 3).
You can't make it with a 2 pixel image because it wouldn't show diagonal lines but some kind of a grid instead.

Tutorial © Melfina. Do not reproduce in any way without previous permission from the author. Printed from http://celestial-star.net