Making Half-Square Triangles

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    Making Half-Square Triangles

  • Half-square triangles, or HSTs, are fundamental quilt units used in many classic block designs, from the pinwheel to the friendship star. Learn to make them two-at-a-time for double the fun in half the time.

  • Pro Tip

    • This tutorial teaches you how to make two HSTs at a time, so you'll want to start with two same-size fabric squares. Cut them to be 7/8" larger than the finished size you want; go even larger (around 1") if you prefer to center and trim them after sewing.

    1. 1. Mark the Diagonal

      On the wrong side of one square, use an acrylic quilting ruler and mark a diagonal line from corner to corner. Stack the squares right sides together and pin if desired.

      Pro Tip

      • Make your mark on the lighter fabric, so the diagonal line is easy to see. It's fine to use a pencil, since the marks will be hidden inside the quilt.

    2. 2. Stitch Your Squares

      Sew ¼" to the left of the marked line. Rotate the piece and sew again on the other side, ¼" away from the marked line.

    3. 3. Cut and Press

      With a rotary cutter and acrylic ruler, cut along the marked line. Press the seams toward the darker fabric. Trim the excess fabric at the corners.

      Pro Tip

      • When pressing, don't move the iron back and forth like you would when ironing a shirt. Lift the iron from area to area, letting the weight of it push the seam flat. Try not to pull on the fabric either, as this can distort the HST.

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    Making Half-Square Triangles