Half-square triangles
Windblown Square
A square set on point inside a turning frame: four half-square triangles meet to form the centre feature diamond, while accent triangles in the corners spin like a pinwheel against the background.
Cut list
What to cut for one 12 inch finished block. A quarter inch seam allowance is already in every size.
Feature
- 2 squares
- 3⅞"Cut once on the diagonal, layered with the background fabric. Each square makes 2 triangles.
Accent
- 2 squares
- 3⅞"Cut once on the diagonal, layered with the background fabric. Each square makes 2 triangles.
Background
- 2 squares
- 3⅞"Cut once on the diagonal, layered with the accent fabric. Each square makes 2 triangles.
- 2 squares
- 3⅞"Cut once on the diagonal, layered with the feature fabric. Each square makes 2 triangles.
- 8 squares
- 3½"
By region
| Region | Fabric | Units | Cut from |
|---|---|---|---|
| Accent 1 | Accent | 1 | 3⅞" square, cut once on the diagonal |
| Background 1 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Background 2 | Background | 1 | 3½" |
| Background 3 | Background | 1 | 3½" |
| Background 4 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Feature 1 | Feature | 1 | 3⅞" square, cut once on the diagonal |
| Accent 2 | Accent | 1 | 3⅞" square, cut once on the diagonal |
| Background 5 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Background 6 | Background | 1 | 3½" |
| Background 7 | Background | 1 | 3½" |
| Background 8 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Feature 2 | Feature | 1 | 3⅞" square, cut once on the diagonal |
| Accent 3 | Accent | 1 | 3⅞" square, cut once on the diagonal |
| Background 9 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Background 10 | Background | 1 | 3½" |
| Background 11 | Background | 1 | 3½" |
| Background 12 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Feature 3 | Feature | 1 | 3⅞" square, cut once on the diagonal |
| Accent 4 | Accent | 1 | 3⅞" square, cut once on the diagonal |
| Background 13 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Background 14 | Background | 1 | 3½" |
| Background 15 | Background | 1 | 3½" |
| Background 16 | Background | 1 | 3⅞" square, cut once on the diagonal |
| Feature 4 | Feature | 1 | 3⅞" square, cut once on the diagonal |
How it goes together
- Step 1
Cut your pieces
Cut the pieces in the cut list. The sizes are for a 12 inch finished Windblown Square block and already include a quarter inch seam allowance.
- Step 2
Make the half-square triangle units
Sew each pair of triangles along its long edge and press toward the darker fabric. Trim every unit to size before you join it.
- Step 3
Assemble the block
Join the units into rows, then join the rows. Press as you go and square the finished block to size.
Read more
Color value vs hue in quilts
Value is how light or dark a color is. Hue is what we usually call “the color itself.” In quilts, value carries the design — hue carries the mood.
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Quilt block families, explained
Most quilt blocks belong to one of six families — Patchwork, Half-square triangles, Flying geese, Stars, Curves, and Hexagons. Each family is a way of piecing fabric together.
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The quilter’s seam allowance, explained
A seam allowance is the strip of fabric between the seam and the raw edge. Quilters work in a standard 1/4 inch — and getting it right is the difference between a top that finishes flat and one that fights you.
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Try the Windblown Square on a real layout.
Open it on the Design Wall. Try a few colors, see the math, change your mind.