Hour Glass Quilt Block Pattern

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How to Sew an Hour Glass Quilt Block

The Hour Glass quilt block is a timeless classic made from four triangles arranged to create a striking hourglass shape. It's a great block for practicing precision piecing and works beautifully in both traditional and modern quilts.

Materials:

• Two contrasting fabrics
• Rotary cutter, cutting mat & quilting ruler
• Sewing machine, thread & pins
• Iron and ironing board

Instructions:

1. Cut two fabric squares the same size (the size depends on your desired finished block).
2. Place the two squares right sides together. Draw a diagonal line from corner to corner on the wrong side of one square using a ruler.
3. Pin the squares together to keep them aligned. Sew a ¼" seam on each side of the drawn line.
4. Cut along the drawn line to create two half-square triangle units. Press seam allowances to one side.
5. Place the two HST units right sides together with seams matching. Draw a diagonal line from corner to corner on the wrong side of one unit, perpendicular to the existing seam.
6. Sew a ¼" seam on each side of the drawn line.
7. Cut along the drawn line to create two Hour Glass blocks. Press seams open or to one side.
8. Repeat to make as many blocks as needed for your quilt.

Making Half-Square Triangles

On the back of the lighter fabric, draw a pencil line diagonally from corner to corner.

Stack a pair of light and dark squares right sides together. Sew a ¼" seam allowance on each side of the line.

You will end up with something like this:

Now cut along the diagonal line.

Press the seam to set it, then press toward the darkest fabric.

To trim to the exact size, line up the 45° diagonal on your ruler with the seam.

Then carefully trim your block with a rotary cutter.

Making Quarter-Square Triangles

On the back of the lightest square, draw a pencil line 90° to the existing seam on the diagonal:

Butt the central seams:

Sew a ¼" seam allowance on the right and left side of the diagonal line.

Then cut the seam on the pencil line.

How to Resize Quilt Blocks

The first step in modifying any quilt block is to decide on the finished size. You can base this on doubling a pattern, cutting it in half, or working with your available fabric.

Important: Always remove the seam allowance before doubling or tripling the size. For example, if your pattern calls for 3½" squares, subtract the seam allowances (½"), double the finished block size (3" → 6"), then add the seam allowance back (½"). You'll end up cutting a 6½" piece of fabric.

Resizing Square Blocks

Add ½" to your desired finished block measurement. For a 4" finished square, cut a 4½" square of fabric.

Resizing Rectangular Blocks

Add ½" to both the length and width. To double a block that measures 3" × 4", cut a 6½" × 8½" rectangle of fabric.

Resizing Half-Square Triangle Blocks

Add ⅞" to the desired finished block size. For a 4" finished block, cut 4⅞" squares.

Resizing Quarter-Square Triangle Blocks

Add 1¼" to the desired finished block size. For a 4" finished block, cut your squares 5¼".