How to make a double-bar origami envelope

(page 2)

1st picture of double-bar origami envelope

01.

Let us start with the paper's back side facing up.

Prepare to apply a horizontal "Z-fold" and then "unfold" .

2nd picture of double-bar origami envelope

02.

Apply the horizontal "Z-fold" of the step #1 and then "unfold" .

Prepare to apply a horizontal "valley-fold" .