A two part system for creating dungeon floors. First apply the texture you want the floor to have (several are included but you can use any) then apply the overlay on top of that texture to define the individual blocks.
Some textures work better with some overlays and so experimentation will be needed to find the best combination
TO USE: Go into patterns. Select your preffered texture. Apply an overlay, the overlays all begin with x or y and so should be clustered at the bottom of the pattern list