To finish the quilt you will need some cornerstones–20 to be exact!
The color choice is up to you, but I used the same color as the small squares in the sashing blocks. This made a nice alternating color scheme in the sashings.
Begin by cutting your pieces:
20 squares at 3 5/16″ x 3 5/16″
40 squares at 3″ x 3″
Cut the white squares in half diagonally.
Lay the long edge of one white triangle along one side of one of the color squares and stitch at 1/4″. Do your best to center the triangle onto the square.
Add another triangle on the other side.
Press both triangles away from the square.
Trim the “dogears” along the unsewn edge of the color square.
Add triangles onto the remaining sides, keeping the triangles centered on the square
Press the triangles away from the square.
Trim the the block so it measures 4 1/2″ x 4 1/2″ with the intersections 1/4″ away from the edge.
You will need to make 20 of these for the quilt!