fading border

When the borders of a picture fade out gradually, instead of meeting a sharp outline.

Examples

• Danbooru post #7444856
• Danbooru post #675679
• Danbooru post #482342

See also

• Tag Group:Image Composition
• Blurry edges
• Diorama
• Radial gradient background
• Vignetting

This tag implicates border (learn more).