Well, as promised here are techniques I use to create spike-looking brushes like iceytina's on Deviantart.com. Due to time constraints, I'm only including a final screenshot of my output. You can figure out the rest.

1. Open up a new RGB image - transparent
   
   
2. Set your colors back to black and white. (If black is the forefround, more black will appear and vise versa for white)
   
   
3. Now, Filters | Render | Nature | Flame
   
   
4. Under Render tab, select "Custom Gradient" For now, don`t change anything else, but you can experiment later.
   
   
5. Under Camera tab, adjust the zoom of the flame to fit the screen as desired (may have to adjust again after the next step)
   
   
6. Click the Edit tab at the top of the window
   
   
7. Under Variation, click linear
   
   
8. Play with the speed, randomize and direction buttons.
   
   I don`t understand the direction button entirely, but the middle one is the one that will be rendered. Those that are around it are variations of it. If you like one of the variations better than that middle one, click on it, and now it becomes the middle. Keep playing with the settings until you get one you like.
   
   
9. Click Ok and readjust the zoom and x/y settings to fit the render where you want it to be positioned on the screen.
   
   
10. You can also save your settings for later use within the flame window.
    
    
11. Exit out of the Flames tool.
    
    
12. Convert image to grayscale (Image | Mode | Grayscale)
    
    
13. Flatten your image .... Image | Flatten Image
    
    
14. Save it as a .gbr brush in your gimp brush folder.
    
    
15. Save your xcf file if you want to edit it later.
    
    
16. Refresh you brushes and start brushing!

Here`s a pic of my brush!



The background is actually transparent. I don`t know how it`s showing up for you, but it should be clear.

Y'all owe me for sharing this secret! I was going to keep it to myself. :w:

Art

I copied fencepost's tutorial from Gimp Talk and brought it here. It's an easy and cool tutorial and I like the results.

My spikey brush. Example of brush is on the right above the colored ellipse.

Thanks Fencepost! I managed to also make a brush for GIMPressionist as well.

That is a cool idea Mahvin! i like also how you used
and thank to fencepost for the tut

Cool. You mean you made a gbr and a pgm brush? Never thought of Gimpressionist. WTG mahvin!

Yes, both. I figured "why not"? Hehehe.

LOL, here's my spikey gimpressionist brush in action. Poor chicken.

BTW, don't forget to invert the colors (I did) if you made a gbr from it first.

I never caught on to GIMPressionist before now, and it can create some pretty cool effects.

O!

I have done the same thing, mahvin. Never used it because I didn't know how.

There looks to be a lot to learn inside there. Too bad all these things don't come with instructions.

Love your chicken-little "O".

Thanks Molly.

The Gimp manual has stuff about Gimpressionist in it if you don't mind wading through all that stuff.

http://docs.gimp.org/2.6/en/plug-in-gimpressionist.html

I had already posted that. GMTA! (great minds think alike)

Anyway, Fencepost just added to the contribution of brushes for it, haha.

I didn't understand some of the settings on the Orientation tab, and the doc helped clear that up.

Thanks "O". I just waded through the whole thang and don't know what I read. Anyway I bookmarked it to use on my next project.

I haven't used Gimpressionist in a couple of years, I think. Time for me to start playing again.