When an artist begins to tear down the moldy wallpaper in her house, you can imagine that the discards won’t end up in the trash. They’ll end up in more art—and, in this case, they’ve ended up spreading like the spores that they are, into an art gallery exhibition and also a permanent collaborative installation in the guest room of a pristine Issaquah home, owned by the father of another artist. Mold: the great unsung Northwest art medium. The artists are Francesca Lohmann and Agata Michalowska. (Cullom Gallery, 603 S Main St, 340-8000, 10 am–5 pm, free)