UIStroke applied to a GuiObject with a UICorner leaves behind 'rounded artifacts'

Direct Links

Bug doesn’t have any one specific place or destination it happens in, it is reproduceable anywhere.

System Information

• OS: Windows 10 Home
• CPU: Intel(R) Core™ i7-9700K CPU @ 3.60GHz
• GPU: NVIDIA GeForce GTX 1050 Ti
• Memory: 16.0GB

Reproduction Steps


Bugged UICorner.rbxm (10.4 KB)


• Insert a ScreenGui under StarterGui.
• Insert a Frame under the ScreenGui, and add a UIStroke and UICorner. Adjust thickness or colors as needed to make it stand out more.
• For best results, make sure the UIStroke and Frame share the same color, preferably a darker shade.

Expected Behavior

I expect for the artifacts to not be there; for it to be completely filled in between the stroke and the edge of the frame.

Actual Behavior

There will be some artifacts between the corner and the stroke where it’s not completely filled in, as if it’s not ‘masking’ correctly?



Issue Area: Engine
Issue Type: Display
Impact: Low
Frequency: Constantly
Date First Experienced: 2021-05-02 00:05:00 (-05:00)
Date Last Experienced: 2021-06-27 22:06:00 (-05:00)


I am having this same issue. See below:

Artifacts depend on scaling/size of the screen? This occurs when using scale instead of offset for the size.

With artifact:

Without artifact:


Replication with maximum contrast (36.0 KB)


I found a post mentioning this from March 5th 2022 8:00 PM UTC.

This occurs for me with both sizing methods.

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