Shoo Fly quilt block
A nine patch with half-square triangles in the corners — the shortest possible step from patchwork into pieced triangles, and the block most teachers reach for second.
Also known as Shoofly, Hole in the Barn Door variant.
Shoo Fly appears under that name in early twentieth-century pattern columns and is closely related to Churn Dash and Hole in the Barn Door; the family shares a nine-patch skeleton and differs only in what fills the corners and sides. The name is one of many that came out of newspaper and magazine pattern syndication, when the same geometry could carry three different names in three different states.
Shoo Fly cutting chart
Cut sizes include a ¼″ seam allowance: ½″ on squares and rectangles, ⅞″ on half-square triangles, and 1¼″ on quarter-square triangles. Pick a finished block size:
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 2⅞" × 2⅞" | 2 | cut once on the diagonal → 4 triangles |
| Background | Square | 2½" × 2½" | 4 | finishes 2" × 2" |
| Dark | HST square | 2⅞" × 2⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | Square | 2½" × 2½" | 1 | finishes 2" × 2" |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 3⅞" × 3⅞" | 2 | cut once on the diagonal → 4 triangles |
| Background | Square | 3½" × 3½" | 4 | finishes 3" × 3" |
| Dark | HST square | 3⅞" × 3⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | Square | 3½" × 3½" | 1 | finishes 3" × 3" |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 4¼" × 4¼" | 2 | cut once on the diagonal → 4 triangles |
| Background | Square | 3⅞" × 3⅞" | 4 | finishes 3⅜" × 3⅜" |
| Dark | HST square | 4¼" × 4¼" | 2 | cut once on the diagonal → 4 triangles |
| Dark | Square | 3⅞" × 3⅞" | 1 | finishes 3⅜" × 3⅜" |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 4⅞" × 4⅞" | 2 | cut once on the diagonal → 4 triangles |
| Background | Square | 4½" × 4½" | 4 | finishes 4" × 4" |
| Dark | HST square | 4⅞" × 4⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | Square | 4½" × 4½" | 1 | finishes 4" × 4" |
| Fabric | Shape | Cut size | Qty | Notes |
|---|---|---|---|---|
| Background | HST square | 5⅞" × 5⅞" | 2 | cut once on the diagonal → 4 triangles |
| Background | Square | 5½" × 5½" | 4 | finishes 5" × 5" |
| Dark | HST square | 5⅞" × 5⅞" | 2 | cut once on the diagonal → 4 triangles |
| Dark | Square | 5½" × 5½" | 1 | finishes 5" × 5" |
How it goes together
Four half-square triangles for the corners, four plain squares for the sides, one for the centre. Make the HSTs first and trim them square before you assemble, because a corner unit that is a hair small will pull the whole block out of true.
Tips
- Make HSTs oversized and trim to exact size — it is faster than unpicking a block that will not lie flat.
- Keep all four corner triangles pointing outward from the centre; a rotated corner is the most common assembly error in this block.
- High contrast between the triangle fabric and the background is what makes the block legible from across a room.
How much fabric for a Shoo Fly quilt?
Yardage for a whole quilt of Shoo Fly blocks, computed the way the studio does it — every piece packed across a 40″ usable width with 10% added for waste.
| Quilt size | Blocks | Finished | Top fabric | Backing | Binding |
|---|---|---|---|---|---|
| Baby 36×48 | 12 | 36" × 48" | Background 1⅜ yd · Dark ¾ yd | 2½ yd | ⅜ yd |
| Throw 60×72 | 30 | 60" × 72" | Background 3⅜ yd · Dark 1¾ yd | 3⅞ yd | ½ yd |
| Queen 90×108 | 72 | 96" × 108" | Background 7¾ yd · Dark 4 yd | 8¾ yd | ⅞ yd |
What it looks like in a quilt
A single block only tells you half the story. Set sixteen of them together and the secondary pattern appears where the blocks touch:
Shoo Fly questions
What is the difference between Shoo Fly and Churn Dash?
Both are nine-patch blocks with HST corners. Shoo Fly has plain squares on the sides; Churn Dash has split rectangles there, which is what creates the churn-handle look.
What size squares for a 12 inch Shoo Fly?
The grid units finish at 4 inches. Cut plain squares at 4½ inches and HST squares at 4⅞ inches, then cut those once on the diagonal.