Knockout Option in Advanced Blending Not Working

[PriyR]

I have Photoshop 20.0.9 and I am trying to create a knockout effect. But the shallow knockout option in advanced blending option is not working. How can I fix this?

[Michael J. Hoffman]

Can you explain in more detail what it is that is not working? Can you show us a screen shot including your layers panel?

See this help page for details on how to use the knockout feature:

https://helpx.adobe.com/photoshop/using/knockout-reveal-content-layers.html

[Michael J. Hoffman]

Also, I wonder if you have set the Fill opacity to 0% for your knockout layer?

[PriyR]

Hi Michael,

Thank you for replying. 

Sharing a screenshot. I want to knockout the polygon so that yellow is visible in the background. 

This is what I am trying to do - choose polygon layer> Blending option> Shallow in knockout> reduce the fill opacity to 0%. 

[Michael J. Hoffman]

Hi Priy,

Thanks for including your screen shot. It clearly shows the issue. A shallow knockout will punch through the layers in a group, and stop at the first layer below the group. If you want to achieve your desired result, put the polygons in a group, and have the yellow solid color layer be the first layer under the group:

[PriyR]

Thanks Michael!