Triangle Combination Quilt Block Pattern

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How to Sew a Triangle Combination Quilt Block

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

Materials:

• Fabric in different colors and patterns
• Rotary cutter, cutting mat & quilting ruler
• Sewing machine & thread
• Batting & quilting pins

Instructions:

1. Cut your fabric into triangles using a rotary cutter, cutting mat, and quilting ruler. The size depends on your quilt design — you can cut uniform triangles or mix sizes for a more dynamic look.
2. Arrange your triangles on a flat surface, experimenting with color and pattern combinations until you find a layout you love.
3. Place two triangles right sides together and sew along one edge using a ¼" seam allowance. Repeat until all triangles are sewn in pairs.
4. Take two pairs and place them right sides together, aligning the seams. Sew along one edge to join. Continue adding pairs until all triangles are assembled.
5. Press your seams to one side to create a flat surface.
6. Layer your quilt top with batting and backing fabric. Pin all three layers together with quilting pins.
7. Quilt the layers together using a straight stitch, motion quilting, or your preferred technique.
8. Trim the edges and add binding to finish.

Happy quilting! Adjust the size and design to suit your preferences.

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.

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: 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".