15.
Unfold and draw a line on the crease.
16.
Valley fold such that the top of triangle is aligned to the black line.
This will be the same folding if we apply the valley-folding along the red dash-line shown in the step #15.
ONCE a boy a Rosebud spied, Heathrose fair and tender, All array'd in youthful pride,-- Quickly to the spot he hied, Ravished by her splendour. Rosebud, rosebud, rosebud red, Heathrose fair and tender! Said the boy, "I'll now pick thee, Heathrose fair and tender!" Said the rosebud, "I'll prick thee, So that thou'lt remember me, Ne'er will I surrender!" Rosebud, rosebud, rosebud red, Heathrose fair and tender! Now the cruel boy must pick Heathrose fair and tender; Rosebud did her best to prick,-- Vain 'twas 'gainst her fate to kick-- She must needs surrender. Rosebud, rosebud, rosebud red, Heathrose fair and tender!