Jonas Ronnegard has recently shared a guide to masking out alphas that you stamp inside of Substance Painter.
“I often get asked about how to Mask out alphas that you stamp inside of Substance Painter, so I created a tutorial on how I do it,” stated the artist.
You can also get the Masked Alphas tool by Jonas here. His SP tool will allow you to add custom masks to use together with any Alpha. Basically, instead of having to mask out details for every stamp you make, you can now create a mask once and use it infinite times.
You can learn more here.