A, miura-ori folded, object consists of parallel creases and zigzag creases. The zigzag creases work in pairs. If, in a pair of creases, both zigzags have the same corners, then the overall result is a surface that is straight.
Let us have a look at three strips of paper with reverse folds. The beginning corners are 35_45_55 degrees.The resulting corners are 110_90_70 degrees.
I did this test with a strip of paper with alternating beginning corners, 40_50 degrees. The strip curves.
When pairs of unequal corners are used to form a miura-ori object the result will be a surface with a curve.
- left 45_45
- middle 40_50
- right 35_55