Step 1:
One side of the paper is colored and the other is white.
Fold in three parts of the same size.

Step 6:
Use the prefolded lines as guidance

Step 5:
Prefold the edges to the centerline

Step 2:
Fold over the purple line

Step 4:
Prefold in half over both lines.

Step 3:
Pull the upper layer upwards and fold over this line. Then push the upper layer downwards again.

Step 10:
Fold over this line and turn the model.

Step 8:
Fold over these two lines

Step 9:
Fold the edges backwards.

Step 7:
Fold over these lines

Step 16:
Fold the cushion upwards

Step 15:
Make the same folds on the other side of the cushion.

Step 12:
Fold the corners inwards over the white lines and the edges straight upwards over the purple lines.

Step 11:
Fold over these four lines.

Step 14:
This is how the model looks from below.

Step 13:
If necessary, valley-fold the cushion a little smaller first, see picture below.