Small Triangles Quilt Block Pattern

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How to Sew a Small Triangles Quilt Block

Sewing a small triangles quilt block is a fun and rewarding project. Here's what you'll need and how to make it.

Materials:

• Fabric pieces in different colors and patterns
• Sewing machine & thread
• Ruler & rotary cutter or scissors
• Cutting mat
• Iron and ironing board

Instructions:

1. Cut your fabric into squares of the same size — 4-inch squares are a good starting point.
2. Take two squares of different fabrics and place them right sides together. Draw a diagonal line from corner to corner on the wrong side of one square.
3. Sew a ¼" seam on both sides of the diagonal line, then cut along the line to create two half-square triangles.
4. Press the seams open on both half-square triangles.
5. Place one half-square triangle right sides together with another, aligning the seams in the center. Draw a diagonal line from corner to corner on the wrong side of one.
6. Sew a ¼" seam on both sides of the diagonal line, then cut along the line to create two quarter-square triangles.
7. Press the seams open on both quarter-square triangles.
8. Place the two quarter-square triangles right sides together, aligning the center seams. Sew a ¼" seam on both sides of the center seam.
9. Trim the block to your desired size — 3½" is a good finished size for a small triangles block.
10. Press the seams open.
11. Repeat to create as many blocks as needed, then arrange and sew them together to create your quilt top.
12. Add batting and backing fabric, quilt as desired, and finish by binding the edges.

Enjoy your beautiful small triangles quilt!

Making Half-Square Triangles

This is a great technique that 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.

Four Patch Piecing

The secret to a perfect four patch is pressing seams so they butt together when joined. You can make a four patch by cutting individual squares (great for scrappy quilts) or using pre-joined strips for speed.

Cut two A squares and two B squares in your required size. Using chain piecing, join an A square to a B square, right sides together, with a scant ¼" seam allowance. Press toward the dark fabric. Your result:

Press all seams toward the dark fabric so they butt up. Place the two A/B units right sides together with butted seams, pin if needed, and join with a scant ¼" seam allowance. Press.

Wider Application

This technique applies to all kinds of four patch blocks. As long as a block has a 4×4 grid — no matter how many pieces — the basic principles apply. Keep pressing seams in pairs of opposite directions and piecing will be smooth sailing.

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: When working from a pattern's cutting instructions, 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".