Shadow Logic

When I’m fiddling around with the GIMP, I often find the colors in my piece slightly plain. Usually it’s not too much of a problem, but when I really get nervous about it I resort to something called scanlines. Scanlines are simple patterns that tend to add some texture to images. Using them is totally up to you: sometimes they really spice up an image, but other times they degrade the quality of it. In this tutorial I’ll cover the basics of scanlines, how to make them, how to use them, and show how they affect images.

Difficulty:
Beginner
Program
The GIMP (2.4)
Needed Time
about 7 minutes

Take a look at these two images. One uses scanlines, the other one doesn’t. The one with scanlines has a bit of a texture overlaying it. If you look closely you can see that the effect is achieved with light, diagonal lines. This pattern is one of the most commonly used, either going from top right to bottom left or vice versa. To use it, you simply make it into a transparent pattern.

Making the scanlines

Open the GIMP, go to File » New…, and make a new 6×6 image. It needs to be transparent, so delete the Background layer and make a new one. (Layer » New Layer…)

Select the Pencil Tool and look for the pre-included brush called Circle (01). Draw as shown in the picture to the left. (Tip: It’s tricky to draw accurately from the normal view. Zoom it to about 800% to se exactly what you’re drawing up close. Another tip: Hold down Shift to draw a straight line.)

Save the image as scanlines1.pat. Be sure to put it in your GIMP Patterns folder. Go to the patterns tab in the Layers, Channels, Paths window and click the refresh button.

Using the scanlines

Open the image you want to add scanlines to. Create a new layer (Layer » New Layer…) and name it Scanlines. Adjust the Opacity to around 20-35.

Select the Bucket Fill tool. Check that it’s set to Pattern fill, and that you selected the scanline pattern you just made. With the Scanlines layer selected, click once inside the image. The scanlines should appear lightly over your original picture. If it doesn’t look right, adjust the opacity. If the image appears too dark, you could try inverting the colors. (Colors » Invert) Experiment with different techniques until you’re satisfied. Save the image and you’re done!

Try experimenting with other patterns too. Instead of drawing three lines you can try drawing one, or you could flip the pattern. Have fun with it!

This entry was posted on Sunday, January 27th, 2008 at 8:48 pm and is filed under GIMP. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.