When a carpenter fits a cabinet against an old wall, nobody straightens the wall. They push the board up close, set a compass to the widest gap, and run its point down the plaster while the pencil leg follows along the wood, so every bulge and dip in the wall is copied onto the board. Then they cut to the line, and a straight board comes out exactly as crooked as the wall, and the gap vanishes. It’s called scribing, the same word as for the people who copied manuscripts by hand, and it’s the same job: copy faithfully, mistakes included. The only way to make that joint disappear was for the board to stop being straight.