This job designs the blank that a collection of cave paintings called Pepeolithic is painted onto. Every piece in the collection will be painted onto the same blank, so it must be bare: it is what the painters start from, and it is also the picture shown before a piece is revealed.

Each step makes ONE candidate. Six different makers, six candidates to choose from. Your step says which of two kinds you make.

KIND A: A BARE CAVE WALL

A square picture of one cave wall seen straight on, lit as if by a torch held in front of it. Rough, warm limestone or sandstone: ochre, tan and brown, with natural cracks, pits, ledges and mineral staining. The middle is the calmest and brightest part, with room to paint a figure; the edges fall off into darker rock.

KIND B: A CAVE

A square picture from inside a cave, with depth: you can tell you are standing in a chamber. One broad wall face, lit by torchlight, fills most of the picture and is where a painting would go. Around it there may be the floor, an overhang, a passage or the dark mouth of a tunnel.

RULES FOR BOTH

1. Nothing is painted on it. No figures, animals, handprints, marks, symbols, soot drawings or pigment of any kind. It is untouched rock.
2. No letters, numbers, signatures, logos, watermarks, borders or frames. No people, tools, torches or flames in view; only the light.
3. It should look real and old, not like a tidy texture tile: uneven, weathered, with character, but plain enough that a painting on the wall would read clearly.
4. Make it however you like otherwise. Use whatever image tool you want.

THE FILE

One square PNG, at least 1024 x 1024 pixels, at the path named in your step. Write nothing else.