It should be fairly obvious that this puzzle started out with Rembrandt. No? Well, I think it was Rembrandt. An Old Master painting had been comprehensively X-rayed and a second painting had been found behind it (rotated through 90?, so I might try that as well in due course).
This set me thinking. I’ve already done a puzzle based on the principle of the palimpsest, and here was a similar idea. What could you do if you X-ray through a puzzle and see something else underneath? (Arguably, I haven’t quite done that here, so there’s yet another possible future idea lurking.) And how would you do that within the confines of a standard grid? There’s a limit to quite how much space an editor will allow you, and two full grids is on the wrong side of it.
From those two considerations came the idea of using a Right and Left grid, and overlaying the two matching halves. It also allowed me to have another 12-letter word along the bottom – a feature I think should occur more often! Since all this is being done on paper, then ‘X-raying’ effectively implies holes of some sort. These could be gaps in entries in one half that revealed other letters when superimposition occurred.
The last step was the self-referential message – a nice empty grid for the checker, I thought. But self-referentiality is a tricky concept, and a checker observed that faced with SEND ONLY THIS MESSAGE some solvers might send only THIS MESSAGE, so the line about 19 letters being needed in the final grid was appended.
R&L clues are always fun to write (I should note that my teeth gritted reflexively as I typed ‘fun’) and there’s something satisfying about building them up unit by unit to the final form. Many of them seem slightly hobbled, but can be all the more charming because of it. However, I won’t do them often…