Whether you've made a selection with Photoshop tools or used a plugin you'd want your selection to look nice and smooth on a new background. This happens when the edges of the object blend with the background colors. If the edges of the selected image were not softened or feathered during the process of selection you may shade them in Photoshop.
All you have to do is:
No shading |
5 px shading |
15 px shading |
50 px shading |