Exploring the notion of curve-following corrugations, I drew a section of a sine wave, placed a series of graduated squares diagonally along it, constructed diagonal bisectors and extended them to the bounding boxes. then tiled, mirrored and flipped copies to construct a sine-wave that extended over an A4 page:
Although tiny, I used a stylus to score the necessary creases then spent a couple of hours delicately collapsing it.
I had been exploring corrugations that followed curved lines, as you do, and sort of worked out that you needed a quadrilateral face with equidistant gutters either side, but my rough approximations were foldable but not pretty:
Then I saw a published paper, about the same thing, that suggested square/rhombi arranged diagonally to follow the line, organised diagonal-based accordion pleats, and a scale factor bigger of the same shape for the gutter creases and bingo, problem solved.
Flat-foldability is a thing, there is lots of maths in it, but it is so satisfying to have manually derived something that was subsequently proven (*flex*).