This tip was submitted by Larry Stevens back in April of 1997
Make a duplicate of your original sprite (Ctrl + D).
Change the color picker to black and fill the duplicate with it by
clicking this icon, 
.
Apply the 
Effects icon, Blur filter to the black sprite with default settings.
Change the color picker to white. Click on the shapes tool 
icon and drag a rectangle
over your black sprite about 15 pixels bigger in all directions (watch your status bar to
see the pixel size). Right click this and click Create.
Right click it again, and click Send to Back. Drag a box
around both the original and white sprites, center them 
and
flatten them together (Crtl + F).
Click on the Effects icon Sprayed Strokes effect. With
your black & white sprite selected, click apply.
Click the Cutout icon 
Select Region Color tab. Set it as follows:
Click the Select Color Region wand in the left corner of the Cutout palette and click in the black area of the sprite. Right click and select Erase. You image should now look like this:
