If You want simpler way, there are good scripts already for this.
Method 1.
shape paths:
http://registry.gimp.org/node/59- create a canvas of your choice, for example 1000x1000px
- menu>script-Fu>Shape paths. Star
center X: 500
center Y: 500
outer radius: 400
inner radius 250
number of points: 12
fill path: yes, choose your color
Tweak shape further with transform tools, if needed.
Add stroke using Layer effects. It´s best to add stroke last if You warp/shear/transform the bubble.
Method 2.
Path waves plug-in:
http://sourceforge.net/projects/gimp-pa ... s/scripts/- new image
- use ellipse selection tool to create an ellipse
- menu>select>to path
- Go to paths dialog box, right-click the path and choose: decorate/periodic wave/triangle
You might want to run with the default parameters first and then try again.
Right-click the new created path>path to selection.
Go to layers, use bucket fill for the selection.
Method 3. This is the easiest.
Use path tool to create your custom bubble. Takes 3 seconds to make similar to your example.
Right-click the new created path>path to selection.
Go to layers, use bucket fill for the selection.
Add stroke.