I'm not sure about elements, but in full fat Photoshop...
In the layers pallette or the blending options window - there are two opacity sliders. One is the main opacity, and the other is FILL opacity. If you take the fill down to zero, the main body of the sprite will disappear but the effects (ie stroke and glow) will remain.
In the layers pallette or the blending options window - there are two opacity sliders. One is the main opacity, and the other is FILL opacity. If you take the fill down to zero, the main body of the sprite will disappear but the effects (ie stroke and glow) will remain.