Place a dark strip on top the light strip and sew the full length. You now have dark, light, dark setup. Repeat with your three remaining cut strips. This will give you a light, dark, light setup. We will now press these setups.
Seams are always pressed toward the darker fabric.
Do not open the seam. Using your steam iron, lightly press the two setups, being careful not to stretch or distort your straight setups. Again go to your cutting mat and lay the two pressed setups one on top of the other. First, using your ruler, make a straight cut to cut the selvage off the two strips. Use your ruler to make the cut square with the bottom of the strips.