Step 3: Add Some Cracks to Your Background Tile
From the tools palette, choose the paintbrush. Change the paintbrush size to 3 Invert the Foreground/Background colors so that the foreground color is white.
Draw a few (3 is usually enough) squiggly "crack" throughout the image, keeping theme -> diffuse and change the setting to 10. Click OK.
You may have to undo and play with this to get it the way you want it so that it does not look bad when you tile it. I suggest not putting the lines too close to the edges.
The final step is to choose Filter -> blur twice to soften the look of the tile.
Now choose Save, name your tile and save it to the appropriate folder on your computer. You are all set to use your tile to create a classy, distinctive background for your webpage.
By experimenting with the tools, you can create any number of beautiful marble and other patterned tiles for your webpage with Pixlr.