Magic Box quilt block

A 6″ finished block measures 6½″ before it’s sewn into a quilt. Each fabric’s yardage is the least that cuts its strips across the width of fabric, with a strip to spare for straightening.

Worked out by @quarterinch/cutting · ¼″ seams included · strips cut across 42″ of usable width · the letters are the pieces the sewing steps name

A 9″ finished block measures 9½″ before it’s sewn into a quilt. Each fabric’s yardage is the least that cuts its strips across the width of fabric, with a strip to spare for straightening.

Worked out by @quarterinch/cutting · ¼″ seams included · strips cut across 42″ of usable width · the letters are the pieces the sewing steps name

A 12″ finished block measures 12½″ before it’s sewn into a quilt. Each fabric’s yardage is the least that cuts its strips across the width of fabric, with a strip to spare for straightening.

Worked out by @quarterinch/cutting · ¼″ seams included · strips cut across 42″ of usable width · the letters are the pieces the sewing steps name

For the 6″ block. Choose another size above and these steps follow it.

1. Make 4 half-square triangle units

   Sew a Background A triangle to a Dark A triangle along their long edges. Press toward the Dark. Each measures 2″ (1½″ finished).

2. Make 4 rail units

   Sew the Background B and Dark B rectangles together along their long edges. Press toward the Dark. Each measures 3½″ × 2″ (3″ × 1½″ finished).

3. Add 2 corner triangles

   Sew the Dark D triangle across each corner in turn, along its long edge, and press toward the triangle.

4. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

5. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

6. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

7. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

8. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

9. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle. Each measures 3½″ (3″ finished).

10. Sew the units into 3 rows

    Lay out the units as in the picture and sew them into 3 rows. Press the seams in row 1 to the left, row 2 to the right, and so on, so they nest when the rows are joined.

11. Join the rows

    Join the 3 rows, matching and nesting the seams where they meet. Press the long seams open or to one side. The block measures 6½″ (6″ finished).

For the 9″ block. Choose another size above and these steps follow it.

1. Make 4 half-square triangle units

   Sew a Background A triangle to a Dark A triangle along their long edges. Press toward the Dark. Each measures 2¾″ (2¼″ finished).

2. Make 4 rail units

   Sew the Background B and Dark B rectangles together along their long edges. Press toward the Dark. Each measures 5″ × 2¾″ (4½″ × 2¼″ finished).

3. Add 2 corner triangles

   Sew the Dark D triangle across each corner in turn, along its long edge, and press toward the triangle.

4. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

5. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

6. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

7. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

8. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

9. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle. Each measures 5″ (4½″ finished).

10. Sew the units into 3 rows

    Lay out the units as in the picture and sew them into 3 rows. Press the seams in row 1 to the left, row 2 to the right, and so on, so they nest when the rows are joined.

11. Join the rows

    Join the 3 rows, matching and nesting the seams where they meet. Press the long seams open or to one side. The block measures 9½″ (9″ finished).

For the 12″ block. Choose another size above and these steps follow it.

1. Make 4 half-square triangle units

   Sew a Background A triangle to a Dark A triangle along their long edges. Press toward the Dark. Each measures 3½″ (3″ finished).

2. Make 4 rail units

   Sew the Background B and Dark B rectangles together along their long edges. Press toward the Dark. Each measures 6½″ × 3½″ (6″ × 3″ finished).

3. Add 2 corner triangles

   Sew the Dark D triangle across each corner in turn, along its long edge, and press toward the triangle.

4. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

5. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

6. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

7. Add a corner triangle

   Sew the Dark D triangle across the corner, along its long edge, and press toward the triangle.

8. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle.

9. Add a corner triangle

   Sew the Background A triangle across the corner, along its long edge, and press toward the triangle. Each measures 6½″ (6″ finished).

10. Sew the units into 3 rows

    Lay out the units as in the picture and sew them into 3 rows. Press the seams in row 1 to the left, row 2 to the right, and so on, so they nest when the rows are joined.

11. Join the rows

    Join the 3 rows, matching and nesting the seams where they meet. Press the long seams open or to one side. The block measures 12½″ (12″ finished).