Creating tileable marble textures with the GIMP

To create textures for my Pantheon Deorum image, I needed a way to make marble textures using the GIMP image editing program. I adapted some techniques from existing Photoshop tutorials. The whole process is presented in this short tutorial. The final result should look similar to this and is fully tileable:

Create a new image with your desired size. In this tutorial, 256 x 256:

Create Solid Noise (Filters → Render → Clouds → Solid Noise) with the following settings:

You may need to adjust the X- and Y-sizes as well as the Detail setting for different levels of marble detail or for different image sizes. Larger images require larger X- and Y-sizes to have the same level of detail. You should now have something that looks like this:

Invert the image (Colors → Invert). Apply the Difference Clouds filter (Filters → Render → Clouds → Difference Clouds) with the same detail setting and X- and Y-sizes as you used for the Solid Noise. If your version of GIMP does not have the Difference Clouds filter, then see Alternate Step 3.

Alternate Step 3: (If you don't have the Difference Clouds filter) Duplicate the background layer which was produced at the end of Step 2. Invert the duplicate layer (Colors → Invert) and set it's Blending Mode to Difference. Now Merge Down so there is only one layer. This produces a result that somewhat resembles Difference Clouds.

Regardless of whether you used Step 3 or Alternate Step 3, the result should look like this:

Use Levels (Colors → Levels) with the following settings:

These settings cause many pixels to be mapped to a brighter value and squeezes the values from black to middle gray to a smaller range. The end result is that the layer becomes brighter and the dark veins are a lot thinner but well defined:

Duplicate the layer and Rotate the duplicate by 90 degrees in either direction (Layer → Transform → Rotate clockwise / counterclockwise by 90 degress). Then set this top layer's Blending Mode to Screen. Play around with the opacity until you get a result you like. The duplicate layer breaks up the uniform looking veins and makes it look a bit less synthetic.

This will produce the image seen at the beginning of the tutorial:

The last two steps were adapted from / inspired by the Realistic Marble Texture tutorial for Photoshop found at http://www.sigsource.com/tutorials.php?act=full&id=59 (the link seems to be down now as of 2010/07/05 17:19). After you are satisfied, you can use this as a tileable marble texture wherever you need one.