My fabric is from an old bench that stood in my childhood home. The bench was broken the fabric was stained but in good condition, so I decided to reuse it.
My pillow was 65 cm. /26" square. I cut 1 length of fabric 155 cm. /61" long and 67 cm./ 26.4" wide. As you can see I got help with the math.
Overlock all sides of the fabric to prevent fraying. I made a 2.5 cm./1" hem at one end of the fabric. Bottom picture shows the hem that will be visible once my pillow case is finished.
The extra 15cm./0.5" on the length of the fabric will make a flap to hold my pillow in place. The extra 2cm./1" on the width is for sewing space.
Just need some one to bring me a cup of coffee.