Shoo Fly Quilt Block Pattern

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How to Sew a Shoo Fly Quilt Block

The Shoo Fly quilt block is a fun and rewarding project for both beginner and experienced quilters.

Materials:

• Fabric squares in two contrasting colors (background and accent)
• Sewing machine & thread
• Scissors & iron

Instructions:

1. Cut two 4½" squares of background fabric and four 2½" squares of contrasting fabric.
2. Take two contrasting squares, place right sides together, and sew a ¼" seam along one edge. Press seam open. Repeat with the other two contrasting squares.
3. Cut each resulting square in half diagonally to make four half-square triangles.
4. Arrange the half-square triangles and the two background squares in the Shoo Fly layout — background squares on opposite corners.
5. Sew the half-square triangles to the background squares with a ¼" seam allowance. Press seams toward the triangles.
6. Sew the two remaining background squares together to form a small square.
7. Sew the small square to the center of the block. Press seams toward the center.
8. Trim the block to 4½" square.
9. Repeat to make as many Shoo Fly blocks as needed.

Once you have several blocks, sew them together to create your quilt top. Have fun experimenting with different layouts!

Making Half-Square Triangles

This technique eliminates the need to directly manipulate the stretchy bias of the triangle. It uses two easy-to-cut squares to produce two 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.

Nine Patch Piecing

The secret to the nine patch is pressing seams so they butt when joined. Cut 5 A squares and 4 B squares in the required size.

Using chain piecing, join a B square to 3 of the A squares, right sides together, with a ¼" seam allowance. The result will be:

Next, chain piece the remaining A and B squares to these units:

Your result will be:

To make this faster, cut A and B strips at the appropriate width and join into A/B/A and B/A/B units. Press every seam toward the dark fabric, then cut across the pre-joined strips:

Same result, but faster:

Press all seams toward the dark fabric so they butt up. Join the B/A/B units to your A/B/A units with butted seams and a ¼" seam allowance. This methodology applies to all kinds of 9-patch blocks — as long as the block has an underlying 3×3 grid, the principle applies.

When it’s not obvious which direction is the dark in complicated blocks, remember the basic ironing plan:

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".