1. A METHOD FOR FORMING A DEVELOPABLE HERRING-BONE PATTERN IN A SHEET OF FOLDABLE MATERIAL COMPRISING THE STEPS OF PLACING AT LEAST ONE OF SAID SHEETS BETWEEN TWO DEVELOPED MOTHER SHEETS WHICH HAVE PREVIOUSLY BEEN SHAPED INTO SAID HERRING-BONE PATTERN; EACH OF SAID MOTHER SHEETS BEING MADE OF A MECHANICALLY RESISTANT MATERIAL WHICH MAY BE DEVELOPED AND RETURNED TO ITS HERRING-BONE PATTERN A PLURALITY OF TIMES WITHOUT RUPTURE; SAID MOTHER SHEETS BEING SANDWICHED ABOUT SAID SHEET OF FOLDABLE MATERIAL SO THAT THE PATTERN OF ONE MOTHER SHEET MATES WITH THE PATTERN OF THE OTHER; RETURNING SAID MOTHER SHEETS TO THEIR UNDEVELOPED, HERRINGBONE PATTERN BY FIRST MOVING ONE PAIR OF ADJACENT TERMINAL PORTIONS OF SAID MOTHER SHEETS TOWARDS THE OTHER PAIR OF ADJACENT TERMINAL PORTIONS OF SAID MOTHER SHEETS IN A FIRST LINEAR PATH TO RESTORE THE FOLDS IN SAID MOTHER SHEETS WHICH ARE TRANSVERSE TO SAID LINEAR PATH AND THEN EXERTING A COMPRESSING FORCE ON THE OTHER TWO PAIRS OF TERMINAL PORTIONS OF SAID MOTHER SHEETS TO URGE SAID PAIRS TOWARD ONE ANOTHER TO RESTORE THE FOLDS IN SAID MOTHER SHEETS WHICH ARE SUBSTANTIALLY PERPENDICULAR TO SAID FIRSTMENTIONED FOLDS; AND REMOVING SAID MOTHER SHEETS FROM THE FOLDED INTERMEDIATE SHEET.