From the pattern description: Wrap your cushion in a square of soft merino wool and fasten the four corners together at the front with a button to make a simple, contemporary cover. The open edges allow a glimpse of the cushion beneath, which can be covered in fabric of a toning or contrasting colors. Choose a large button to make an arresting centerpiece to the flower shape formed by the opening.

Notions:

Sewing needle and pins
1 large button
50 cm (20in) square cushion