There are also some very good freeware graphic editors with layer support. One to look for is Pixia, an outstanding free package that handles layers as smoothly as the commercial competitors (and is some 3 MB in compressed size!). As secondary options, you can choose between Satory Photo XL v2.29 and Serif's PhotoPlus 5. The first one is not as easy to use as other similar packages (at least not in my opinion), while the second one, with its lots of extra features, can only adjust the opacity level of each layer (as far as I know, Satory Photo XL has this same limitation).

MegaLux's Ultimate Paint v1.91f could be an extra option. It doesn't include layering assistance, but its arithmetic filter will do a similar, although more limited, work. There's also a "beef up" adware version of this editor and a shareware one, both of which come with some extra filters and functionality. You might consider PaintStudio Lite too, a new and simple graphics editor that doesn't support layers, but allows you to load two images (one becoming the background image, and the second one, the foreground object) and to merge them with varying opacity levels.

For Linux family users, the standard has always been the GIMP. Now, this gem is freely available for Windows and MacOS X, with practically the same power and tools of the commercial packages. Although it's very stable (so far I've had no problems using it on my PC), it's continuously under development, so be careful, or do not install if you have any doubt. Its developers recommend to set your monitor to, at least, 1024x768 resolution, but I think that's only because The GIMP's many floating toolbars can easily clutter the screen. I used to run the Windows version at 800x600 without problems.

Once you make sure your software support layers, create the fractal images you're going to blend together. Using your favorite fractal program, generate the master image. I have chosen Stephen C. Ferguson's Tiera-Zon v2.8 for this tutorial because of several reasons: it's one of the best generators around, it's quite fast, and it has lots of formulas and color algorithms. Also, there are several online tutorials for this program, in case you need some extra advise on how to use it. See the Links section for more information.

Stephen C Ferguson's Tiera-Zon 2.8

Tiera-Zon opens up with a thumbnail-size "prototype" of the classic Mandelbrot set (1). Enlarge it to at least 320x240 pixels to facilitate your search. To do that, use the XY icon located in the toolbar or select SIZE from the WINDOW menu. Start by looking for an eye-catching motive near one of the borders. For example, go to the larger bug in the frontal antenna-like spike (2), and from there, jump to the Elephant valley (3). Use the following picture as a guide: as steps 1, 2, 3 above. Zoom around a little until something intriguing pops up. Save it because that will be your first image.

For this brief tutorial, we will circumscribe to a few elementary procedures, so keep working with that same motive, applying different filters and coloring algorithms to create new variants. Remember to always save the new image under a different name since you won't wish to overwrite the previous parameter values.

Repeat the same process as many times as you want, until you come up with a couple or so images to work with.