Step 2: Sew the cushion front
Sew the squares into rows using a 1/4" seam and press the seams on each row in opposite directions (eg row 1 to the right, row 2 to the left etc). Sew the rows together to make the creeper face which should end up at 16 1/2" square. Press all the long seams carefully, ensuring you don't end up with fabric tucks at the fold.
Measure across the centre of your creeper's face (should be 16 1/2", but mine was 16 3/8")and cut 2 strips of black fabric this long by 3 1/2" wide. Sew these to the top and bottom of the face and press the seam towards the border. Now measure across the "height" of your face (should be 22 1/2") including the borders and cut 2 strips of black fabric this long by 3 1/2" wide. Sew these to the sides of the face and again press the seam towards the border. If your borders are longer than the central measurement across your centre they will end up being wavy. This would not be a big problem on a small project like this, but on a larger quilt or a wall hanging it would be quite noticeable.