Half-square triangles
Double X
Two crossing X’s of half-square triangles: feature triangles march out from the centre along both diagonals to the corners, leaving a crisp background between the arms.
Cut list
Dimensions for a 12 inch finished block with a standard 1/4 inch seam allowance. Scale proportionally for other finished sizes.
| Region | Role | Pieces | Cut size |
|---|---|---|---|
| Feature 1 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 1 | Background | 1 | 3 7/8" × 3 7/8" |
| Background 2 | Background | 1 | 3 1/2" × 3 1/2" |
| Background 3 | Background | 1 | 3 1/2" × 3 1/2" |
| Feature 2 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 4 | Background | 1 | 3 7/8" × 3 7/8" |
| Background 5 | Background | 1 | 3 1/2" × 3 1/2" |
| Feature 3 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 6 | Background | 1 | 3 7/8" × 3 7/8" |
| Feature 4 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 7 | Background | 1 | 3 7/8" × 3 7/8" |
| Background 8 | Background | 1 | 3 1/2" × 3 1/2" |
| Background 9 | Background | 1 | 3 1/2" × 3 1/2" |
| Feature 5 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 10 | Background | 1 | 3 7/8" × 3 7/8" |
| Feature 6 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 11 | Background | 1 | 3 7/8" × 3 7/8" |
| Background 12 | Background | 1 | 3 1/2" × 3 1/2" |
| Feature 7 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 13 | Background | 1 | 3 7/8" × 3 7/8" |
| Background 14 | Background | 1 | 3 1/2" × 3 1/2" |
| Background 15 | Background | 1 | 3 1/2" × 3 1/2" |
| Feature 8 | Feature | 1 | 3 7/8" × 3 7/8" |
| Background 16 | Background | 1 | 3 7/8" × 3 7/8" |
How it goes together
- Step 1
Cut your pieces
Cut each region using the dimensions in the cut table for a 12 inch finished Double X block. Standard 1/4 inch seam allowance is included.
- Step 2
Sew sub-units
Sew the smallest units first (half-square triangles, flying geese, four-patches), then build outward.
- Step 3
Assemble the block
Join the sub-units into rows or columns, then join the rows. Press as you go. 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.
5 min read
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.
6 min read
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.
5 min read
Try the Double X on a real layout.
Open it on the Design Wall. Try a few colors, see the math, change your mind.