Half-square triangles
Birds in the Air
A flock of half-square triangles all pointing the same way, with open sky in the upper-right corner. Piece six identical HST units and three plain background squares, then sew into three rows so the feature triangles march along the diagonal.
Cut list
What to cut for one 12 inch finished block. A quarter inch seam allowance is already in every size.
Feature
- 3 squares
- 4⅞"Cut once on the diagonal, layered with the background fabric. Each square makes 2 triangles.
Background
- 3 squares
- 4⅞"Cut once on the diagonal, layered with the feature fabric. Each square makes 2 triangles.
- 3 squares
- 4½"
By region
| Region | Fabric | Units | Cut from |
|---|---|---|---|
| Bird Top Left | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Top Left | Background | 1 | 4⅞" square, cut once on the diagonal |
| Bird Mid Left | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Mid Left | Background | 1 | 4⅞" square, cut once on the diagonal |
| Bird Bottom Left | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Bottom Left | Background | 1 | 4⅞" square, cut once on the diagonal |
| Bird Center | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Center | Background | 1 | 4⅞" square, cut once on the diagonal |
| Bird Bottom Center | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Bottom Center | Background | 1 | 4⅞" square, cut once on the diagonal |
| Bird Bottom Right | Feature | 1 | 4⅞" square, cut once on the diagonal |
| Sky Bottom Right | Background | 1 | 4⅞" square, cut once on the diagonal |
| Sky Top Center | Background | 1 | 4½" |
| Sky Top Right | Background | 1 | 4½" |
| Sky Mid Right | Background | 1 | 4½" |
How it goes together
- Step 1
Cut your pieces
Cut the pieces in the cut list. The sizes are for a 12 inch finished Birds in the Air 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
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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 Birds in the Air on a real layout.
Open it on the Design Wall. Try a few colors, see the math, change your mind.