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Magic Box

Diagram of the Magic Box quilt block layout
Design with this block

Techniques used (complete these first)

Two-at-a-Time Half-Square Triangles

HST Unit

Produces two matching Half-Square Triangles (HSTs) from a pair of squares.

  1. Cut one square from each fabric using the 2-at-a-time starting size.
  2. Place the two squares right sides together and mark one diagonal line.
  3. Sew 1/4 inch from both sides of the marked line.
  4. Cut on the marked line to separate the two units.
  5. Press open and trim each HST to unfinished size.

Pro tip: When the pattern needs an odd HST count, this method is ideal for making the final pair without committing to larger batches.

Strip Piecing

Strip Set Unit

Sewing long strips of fabric together before sub-cutting them into smaller units. This increases speed and alignment accuracy.

  1. Cut long strips of fabric to the calculated width.
  2. Align strips right sides together and sew along the entire length.
  3. Press the seams (usually toward the darker fabric).
  4. Use a rotary cutter and ruler to sub-cut the strip set into units at the required intervals.

Pro tip: Check your seam allowance after the first few inches to ensure the total width of the strip set is exactly what the pattern calls for. For strip sets with multiple seams, alternate your sewing direction for each seam to keep the strips aligned and prevent the fabric from warping or leaning. Sub-cut to the unfinished unit size listed in your cutting instructions.

Economy Block (Center-Out)

Economy Block Unit

Construct the Economy unit from the center outward by adding two rounds of corner triangles, trimming between rounds for point accuracy.

  1. Cut one center square plus two triangle rounds from paired squares (each pair cut once diagonally).
  2. Mark or finger-press midpoints on the center square edges and on triangle long edges.
  3. Sew inner-round triangles to opposite sides first, press, then add the remaining two sides.
  4. Trim and square the unit before adding the outer-round triangles to keep points centered.
  5. Repeat opposite-sides-first for the outer round, then final-trim to unfinished block size.

Pro tip: Keep at least a 1/4 inch seam allowance beyond all center-diamond points after trimming; if points land on the trim line, the block was undercut.

Oversize and Trim (The Float)

Triangle-in-a-Square Unit

Intentionally cutting components slightly larger than needed to allow for a perfect trim-down after sewing.

  1. Cut pieces using the 'oversized' formula (usually adding an extra 1/2 inch).
  2. Assemble the unit following standard seam allowances.
  3. Place a square ruler over the unit, aligning the center or diagonal points with the ruler markings.
  4. Trim all four sides to reach the final unfinished block size.

Pro tip: When trimming 'Triangle in a Square', ensure the top point is exactly 1/4 inch from the edge so it isn't lost in the next seam.

Subunits first

Using the techniques listed above, make the following sub units: 1 Economy Block Unit, 2 HST Units, 2 Two-Stripe Unit (legacy)s, 2 Two-Stripe Unit (legacy)s.

Block Assembly

Assembly instructions are currently in the works, check back soon for updates!

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