How to Sew a Diagonal Strip Quilt Block (Beginner-Friendly Tutorial)

6 hours ago
2 min read

Colorful quilt with diagonal strips of floral patterns in red, blue, yellow, and green on fabric. Bright and cheerful design.

Diagonal Strip Quilt Block

There’s something really satisfying about turning simple straight strips into something that looks much more intricate. This diagonal strip quilt block is one of those techniques that feels a bit like magic - you start with basic strip piecing, make one cut, and suddenly everything shifts into a completely new design.

It’s a lovely way to use up scraps or pre-cut fabrics like jelly rolls, and a great opportunity to play around with colour combinations without overthinking it. Because it’s all based on straight seams, it’s very beginner-friendly too. If you can sew a straight line, you can absolutely make this.

The fabric range I've used for this quilt block is the Liberty Fabrics Palace Gardens Collection.

A grid of 20 colorful floral and geometric patterns with various color schemes includes blue, yellow, pink, and green. Bright and cheerful mood.

What you’ll need

8 fabric strips total
Each strip: 2.5" x 8.5"
Sewing machine + basic sewing tools
Rotary cutter + ruler (recommended for accuracy)

Step 1: Create your strip units

Take 4 fabric strips and arrange them in an order you like. Think about how the colours will look once they’re cut and rearranged - high contrast works really nicely here.

Four fabric strips with floral patterns on a white background. Designs include yellow roses, blue flowers, and multicolored blooms.

Sew the strips together along the long edges using a ¼" seam allowance.

Press your seams to one side.

Four fabric strips with floral patterns in blue, yellow, and pink on a white background. Each strip features different floral designs.

Repeat this process with another set of 4 strips so you end up with two strip blocks.

Step 2: Square up (optional but helpful)

If needed, lightly trim your blocks so the edges are straight and even. This helps everything line up neatly later on.

Step 3: Cut diagonally

Take one strip block and cut it diagonally from corner to corner.

Repeat with the second strip block, cutting in the same direction.

You’ll now have 4 triangular pieces.

Colorful, patterned envelopes with floral designs on a white background. Each envelope features different vibrant floral prints in rows.

Step 4: Arrange your block

This is where the design comes together.

Lay out the triangles and rotate them until you create a larger square. You’ll notice the strips now form a diagonal, almost chevron-style pattern across the block.

Triangular quilt pattern with vibrant floral prints in yellow, blue, and red on a white background, arranged in a geometric design.

Step 5: Sew the block together

Sew the triangles together in pairs first.

Two triangular quilt pieces with vibrant floral patterns in yellow, blue, and red on a white background, arranged in a geometric design.

Press the seams, then sew the two halves together to complete your block.

Press again and square up if needed.

Colorful quilt square featuring floral and geometric patterns in yellow, blue, and pink. Set on a white background.

Finished block

You’ll end up with a bold diagonal strip design that looks far more complex than it actually is - one of those techniques that’s really satisfying to make (and a great one to repeat for a full quilt).

I hope you enjoy sewing this block, it’s such a satisfying one to make and a great way to use up those smaller pieces of fabric.

If you’re in the mood to keep sewing, have a look at some of my other quilt block ideas, there are plenty of simple techniques that create really effective designs.

Happy Sewing! Kym

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