Mask opacity in Kantan Mapper

Hi beautiful people,

I am working on my very first projection mapping using Kantan Mapper and encountered a problem. I’ve built a structure out of triangles and would like to switch between projecting on the overall sculpture and projecting only on specific triangles. When I reduce the opacity of the overall mask it produces a gray overlay so the ones below are not visible. Is there a work around this?

Thanks in advance!

Best,

Laszlo