# Decal has white border artifact on metals

**URL:** <https://forums.unrealengine.com/t/decal-has-white-border-artifact-on-metals/400500>\
**Category:** Rendering\
**Tags:** decal, alpha, border, unreal-engine, question\
**Created:** [July 21, 2017, 7:07pm UTC](https://forums.unrealengine.com/t/decal-has-white-border-artifact-on-metals/400500 "2017-07-21T19:07:42Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![LostScout](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@LostScout](https://forums.unrealengine.com/u/LostScout)\
**Post date:** [July 21, 2017, 7:07pm UTC](https://forums.unrealengine.com/t/decal-has-white-border-artifact-on-metals/400500/1 "2017-07-21T19:07:42Z")

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![202905-highresscreenshot00000.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/4/a/e4a89eaeafc83507481fd9641058cd4e2f4424de.png)

This is a png in which there is the blood with the alpha channel. When I drag this decal on to shiny metals materials I continue to get this border. I am pretty sure I am making the alpha map correctly (as this decal looks fine on not-reflective non-shiny surfaces)

How can I get this border gone on my decals??

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**Author:** ![LostScout](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@LostScout](https://forums.unrealengine.com/u/LostScout)\
**Post date:** [July 21, 2017, 7:55pm UTC](https://forums.unrealengine.com/t/decal-has-white-border-artifact-on-metals/400500/2 "2017-07-21T19:55:38Z")

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The problem seems to be in the metallic property. After lowering the metallic property by .2 the borders were gone. I have no clue why that is. Any Idea?

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**Author:** ![Zero-Night](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Zero-Night](https://forums.unrealengine.com/u/Zero-Night)\
**Post date:** [August 9, 2017, 11:37am UTC](https://forums.unrealengine.com/t/decal-has-white-border-artifact-on-metals/400500/3 "2017-08-09T11:37:10Z")

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Metalness doesn’t respond well to transitions between metal and nonmetal surfaces, it’s just an artifact of the metal/rough PBR workflow.

 ![](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/c/3/3c3f818f80af70493f0fee1b753af7f110e63c19.jpeg)

Nothing you can do about it without modifying engine shaders. Just try to have the transition be as short as possible on that channel to reduce the problem a bit.