WTC Quiltstitched with care since 2001

Quilt block

Sister's choice quilt block

Sister's choice is a five-patch block: 25 squares in five rows of five, with eight of them made into half-square triangles. Traditionally it uses two contrasting fabrics, and the dark forms a bold cross with angled points around a nine-patch center. Swap the two fabrics (a light figure on a dark background) and the same block looks completely different.

Sister's choice block: a plum cross with triangle points on a five by five grid, on cream
Plum and cream. The center three-by-three is a nine-patch; the triangles sit on each side of the plum square at the middle of each edge.

How the block is built

Sister's choice block pulled apart into 25 units in five rows
Five rows of five units: 9 background squares, 8 print squares and 8 half-square triangles.

Every unit is a fifth of the block. Row by row, with B for background, P for print and T for a half-square triangle:

RowUnits, left to right
1 and 5B, T, P, T, B
2 and 4T, B, P, B, T
3P, P, B, P, P

The triangles always sit next to a print square at the middle of an edge, with their print half touching that square and facing into the block. So in row 1, the left triangle has its print in its lower-right half and the right triangle in its lower-left half. In row 2 the outer triangles have their print on the side that touches the row 3 print squares. The middle 3 × 3 (rows 2 to 4, columns 2 to 4) is a plain nine-patch with background corners and center.

A sister's choice is sometimes made with plain squares in place of the triangles, which turns it into an all-squares block. Both versions are around; this page covers the triangle version.

Cutting chart (one block)

Finished blockUnitBackground squaresPrint squaresFor the 8 HSTs (background + print)Unfinished block
7½ in1½ in9 squares 2 in8 squares 2 in4 + 4 squares 2⅜ in (or 2½ in to trim)8 in
10 in2 in9 squares 2½ in8 squares 2½ in4 + 4 squares 2⅞ in (or 3 in to trim)10½ in
12½ in2½ in9 squares 3 in8 squares 3 in4 + 4 squares 3⅜ in (or 3½ in to trim)13 in
15 in3 in9 squares 3½ in8 squares 3½ in4 + 4 squares 3⅞ in (or 4 in to trim)15½ in

Squares are the unit + ½ inch; HST squares are the unit + ⅞ inch (exact) or + 1 inch (to trim back to the unit + ½ inch). 9 + 8 + 8 = 25 units, one full five-patch. All sizes checked by calculation. The 10-inch block is the easy one: every plain square is 2½ inches, so a jelly roll or a stack of 2½-inch strips cuts it with no measuring beyond the strip.

Five-patch blocks fit sizes that divide by 5. For anything else (a 12-inch sister's choice, say) the unit is 2.4 inches, which isn't on a ruler; it's better to pick 12½ inches and adjust the setting. The block resizer explains why.

Piecing steps

  1. HSTs: draw a diagonal on the wrong side of the four background HST squares. Pair each with a print square, sew ¼ inch on both sides of the line and cut on it. Press toward the print and trim all eight to the unit + ½ inch.
  2. Lay out all 25 units using the row table. Turn each HST so its print half touches the print square at the middle of the nearest edge.
  3. Sew each row. Press rows 1, 3 and 5 to the left and rows 2 and 4 to the right, so every seam nests with the row above and below.
  4. Join rows 1 and 2, then 4 and 5, then add row 3 between the two halves. Pin at every seam intersection; there are four per row.
  5. Press the row seams in one direction, or open if the block will be heavily quilted.
  6. Measure: 8, 10½, 13 or 15½ inches.

Twenty-five units is a lot to keep straight. Lay the block out on a small board or a piece of batting next to the machine, take each row off to sew it and put it back before starting the next.

Choosing fabrics

Two fabrics with strong contrast are the traditional choice and the clearest. A third fabric works well in the nine-patch center only (the four print squares around the middle), which makes the block look like a cross with a contrasting heart. For a scrappy quilt, make each block in a single print and keep one background throughout, as in the quilt diagram below. Medium-value backgrounds tend to swallow the triangle points.

Common mistakes and fixes

  • A triangle points the wrong way. The print half must touch the print square at the middle of the edge. Lay out the whole block before sewing any row.
  • Rows don't match in length. Five seams per row multiply any seam error by five. Check one finished row against the expected length (the block's unfinished size) before sewing the rest.
  • Points cut off at the block edge. The HSTs were trimmed off center. Put the ruler's 45-degree line on the seam when trimming.
  • Seams fight at intersections. All rows pressed the same way. Alternate the pressing direction row by row.

Quilts made from sister's choice

Sister's choice quilt: 20 blocks in four colors on cream, 4 across and 5 down, with gold sashing
Twenty 10-inch blocks in four prints, 4 across and 5 down, with 2-inch sashing between and around them: 50 × 62 inches.

With sashing the blocks read as separate crosses. Set side by side, the background corners of four blocks meet in a larger square and the crosses link into a grid. The name makes it an obvious pick for sisters or a family reunion: each person makes a block in their own color. Put everyone's name on the label.

Related blocks

For another block built row by row from squares and triangles, see the churn dash or shoofly. The double Irish chain is another five-patch, and the bear's paw moves up to seven. HST sizes for any unit are on the half-square triangle calculator; the quilt block library has every block on the site.

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