How to make a long origami stairs (page 7)

 

11. Apply two "mountain-folds" of the step #10.   Prepare to apply five "mountain-folds" and seven "valley-folds" .

12. Apply five "mountain-folds" and seven "valley-folds" of the step #11.

 

 

 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22