8x8 Oil on Canvas. The canvas has a wide base and painted edges to sit on a shelf instead of hanging, no framing necessary.
Luna moths have always fascinated me since the first night one landed on my hand when I was 8. I put it in an open shoebox and left it outside, the next morning the moth was gone but she'd laid eggs in the box. I left it outside by a walnut tree and got to see the caterpillars hatch.