Called the "Dyer's Polypore" because people use it to make fabric dyes which sounds like another hobby I don't have time for. The PNW version turned out to be a distinct species from the European Phaoleus schweinitzii which is the name field guides have been using for decades.

This is softer than most polypores, I was surprised how easily a chunk came off.

Here's the same piece a few hours later after the stains where I touched the pores have fully darkened.

Magnified! The pores are pretty unusual, shallow and angular.