Is there a way to shade pictures with Paint.net without creating white outlines around the image?

When I put my pictures on any type of a dark background there is a whitish grey outline. If I bring the transparency in closer it makes the picture look very pixely and blocky. Is there a way to get around this? Is there a way to shade pictures with Paint.net without creating white outlines around the image?
Try using feather plugin (checkmark the ';true feather'; option) on the layer with the picture to get rid of the outline





download plugin here:


http://paintdotnet.forumer.com/viewtopic鈥?/a>