Quilt block

Double Irish Chain A quilt block

The chain block of a Double Irish Chain — a five-by-five patch grid whose corner and diagonal squares carry the chain across the quilt.

Also known as Irish Chain (chain block).

Irish Chain quilts go back to the early nineteenth century and possibly further. The double chain uses two alternating blocks: this one, a dense 25-patch, and a plainer partner. Neither block contains the chain — the chain only exists once both are set together, which is one of quilting's neatest illusions.

Double Irish Chain A 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:

FabricShapeCut sizeQtyNotes
AccentSquare2⅞" × 2⅞"12finishes 2⅜" × 2⅜"
BackgroundSquare2⅞" × 2⅞"4finishes 2⅜" × 2⅜"
DarkSquare2⅞" × 2⅞"9finishes 2⅜" × 2⅜"

How it goes together

A 25-patch built from five strip sets, crosscut and reassembled. Strip piecing is not just faster here, it is the only sane way to do it.

Tips

  • Build all five strip sets first, press them consistently, then crosscut and lay out the whole block before sewing rows.
  • This block only works alongside Double Irish Chain B. Making one without the other produces nothing.
  • Consistent pressing across the strip sets is what lets twenty seams nest through the block.

How much fabric for a Double Irish Chain A quilt?

Yardage for a whole quilt of Double Irish Chain A blocks, computed the way the studio does it — every piece packed across a 40″ usable width with 10% added for waste.

Blocks set edge to edge at 12″ finished, no sashing or borders. Change any of that in the studio and the numbers update.
Quilt sizeBlocksFinishedTop fabricBackingBinding
Baby 36×481236" × 48"Background ⅜ yd · Dark ⅞ yd · Accent 1⅛ yd2½ yd⅜ yd
Throw 60×723060" × 72"Background 1 yd · Dark 1⅞ yd · Accent 2½ yd3⅞ yd½ yd
Queen 90×1087296" × 108"Background 2⅛ yd · Dark 4½ yd · Accent 6 yd8¾ yd⅞ 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:

Sixteen Double Irish Chain A quilt blocks set four by four, showing the secondary pattern formed where the blocks meet
Four by four Double Irish Chain A blocks, straight set with no sashing.

Double Irish Chain A questions

What block goes with Double Irish Chain A?

Double Irish Chain B, alternated like a checkerboard. The chain appears only where the two meet.

How many squares are in the chain block?

Twenty-five, in a 5×5 grid. In a 10 inch block each square finishes at 2 inches.

Change one thing and every number follows

Resize the block, swap a fabric, add sashing — the cutting list and the yardage recalculate as you go. No spreadsheet, no re-doing the math.

Try it with Double Irish Chain A