The theme was "silent lives".
It reminded me of about how we wiped out our shared history of the coalmines in this region. I said it before, there is nothing left but ugly scars in the landscape.
And the miners themselves (almost all are gone now), they kept silent about that era. If I remind correctly, back then they didn't even talk about underground. As if it were 2 different worlds, below and above.
I used fibreboard, put tilemortar on it, gessoed it, then an underpainting of acrylic. Finally oilpaint,