Friendship Star Quilt Block Pattern

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How to Sew a Friendship Star Quilt Block

The Friendship Star quilt block is a classic and beloved design built from half-square triangles arranged around a central square to form a striking star. It's a wonderful block for showcasing two contrasting fabrics!

Materials Needed

• Fabric in at least two different colors or prints
• Ruler
• Rotary cutter or fabric scissors
• Sewing machine
• Iron and ironing board

Step-by-Step Instructions

1. Cut two squares of fabric to the same size. For a 4" finished block, cut 5" squares.
2. Place the two squares right sides together, edges aligned.
3. Draw a diagonal line from one corner to the opposite corner on the wrong side of one square.
4. Sew a ¼" seam on both sides of the marked line.
5. Cut along the marked line to create two half-square triangle units.
6. Press the seams open on each unit.
7. Trim the dog ears (small triangles that stick out beyond the seam) from each unit.
8. Arrange the HSTs with background squares to form the Friendship Star layout.
9. Sew the units together in rows with a ¼" seam allowance, then join the rows.
10. Press the seams open and trim the block to your desired finished size.
11. Repeat to create as many blocks as needed for your quilt.

No-Bias Half-Square Triangle Technique

This technique eliminates the need to directly manipulate the stretchy bias of the triangle. It uses two easy-to-cut squares and produces two HSTs at once.

Step 1: Draw the Diagonal Line

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

Step 2: Sew Both Sides of the Line

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:

Step 3: Cut, Press, and Trim

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

Line up the 45° diagonal angle on your ruler with the seam, then carefully trim with a rotary cutter.

How to Resize Quilt Blocks

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

Note: When working from a pattern's cutting instructions, remove the seam allowance before scaling. For example, if your pattern calls for 3½″ squares, subtract the seam allowance (½″), double the finished size (3″ → 6″), then add the seam allowance back (½″) — giving you a 6½″ cut piece.

Resizing Square Blocks

Add ½″ to your 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 3″ × 4″ block, cut a 6½″ × 8½″ rectangle.

Resizing Half-Square Triangle Blocks

Add 7/8″ to the desired finished block size. For a 4″ finished HST block, cut 4⅞″ squares.

Resizing Quarter Square Triangle Blocks

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