Sew and Trim the Attic Windows Mitered Seam
- Place a ruler along the folded diagonal edge as illustrated.
- Draw a line on the visible bottom strip, diagonally along the side of the ruler.
- Sew a seam along the line, starting where the previous seams ended. After you take a few stitches, backspace along them, taking care not to sew beyond the original starting point. Sew all the way to the end of the strips.
- Trim the strips along the diagonal, leaving a 1/4" seam allowance.


