[xxxbewareofmexxx]

1.) Open up a New File.
2.) Set the image size to whatever size you intend your brush to be.
3.) Click on the Advanced Options and a drop down menu should appear. (View Picture 1 Below)
4.) Set the Fill to Transperancy. Now you're all set to begin creating your first GIMP brush.
5.) Create some circles with the Circle Selection tool. Use the Fill tool to color them in black. (View Picture 2 Below)
6.) Right click and Select All.
7.) Save the brush as namedesired.gbr
8.) A pop-up box should appear. (View Picture 3 Below) I usually keep the settings at default.
9.) Now that your brush us saved find where you saved it and right click to cut.
10.) Program Files > Gimp-2.0 > Share > gimp > 2.0 > Brushes
11.) Paste your brush there.
12.) Now in the Gimp Tool Box go to File > Dialogs > Brushes
13.) A pop-up box should appear and in the bottom right hand corner of it click the refresh brushes picture.
14.) Now that your brush is done