If your original square icon has a proper bleed, then there will be no lines. Just make sure the background extends outside the cropping area, for example if your icon is 192px by 192px, make sure the background extends something like 200 x 200.
If your original square icon has a proper bleed, then there will be no lines. Just make sure the background extends outside the cropping area, for example if your icon is 192px by 192px, make sure the background extends something like 200 x 200.