Folding the center

We are going to make the folds in the middle of the mask.

Draw small lines on the left and right sides of the fabric, at: 2cm, 7cm, 12cm and 17cm (0.8in, 2.75in, 4.7in and 6.7in).

These are our folding marks. Hold the fabric on each side at 7cm / 2.75in and fold it over the marks at 2cm / 0.8in from the edge.

Iron to mark the fold. Do the same thing on the bottom of the fabric by folding the fabric at 12cm / 4.7in on the mark at 17cm / 6.7in. Iron the result.