Masking question

I’m having trouble masking only 1 side of my object without the masking wrapping to the other polygroups with a blur effect. I’m unable to mask only the polygons that I have selected. My process is that I hide all areas except the polygroup or area I dont want masked, control click then make all visible and then inverse the mask. I’ve tried turning off mask blur but no effect. Ive also tried sharpening the mask. What is the setting I need to change? I posted a simple cube for example and in this case, I only wanted the top green polygroup masked but it blurred into the yellow and purple. Mask blur is off. thanks!
ZBrush Document

Hello @Room123

In Zbrush, you’re actually masking the points, not the polygons. A polygon is masked when all the points it is comprised of are masked. The semi-shading you see adjacent to masked polygons is because the points that make up the surrounding polygons are partially masked, but those polygons wont be masked unless all of their points are masked.

If you partially hide geometry and mask only the visible polygons, then ONLY those polygons will be masked, even if you see some partial shading around the mask area.