A QuiltPlan piecing guide
Economy Block
A square in a square, twice, every point kept.
An upright center square, four triangles that turn it on point, then four more that turn it upright again. Each round is trimmed so a quarter inch stays beyond every point: the center's corners just meet the seams of round two, and round one's points just meet the seams the whole unit is sewn in with. Round two is exactly QuiltPlan's Square in a Square.
What you cut, for one unit
Shown for a unit that finishes at 8″, with a 4″ center. Every size is in the chart below.
| Finished unit | Center, cut 1 | Round 1: cut 2, cut once | Trim round 1 to | Round 2: cut 2, cut once | Trim the unit to |
|---|---|---|---|---|---|
| 4″ | 2½″ | 2¾″ | 3⅜″ | 3¼″ | 4½″ |
| 6″ | 3½″ | 3⅜″ | 4¾″ | 4¼″ | 6½″ |
| 8″ | 4½″ | 4⅛″ | 6⅛″ | 5¼″ | 8½″ |
| 10″ | 5½″ | 4⅞″ | 7⅝″ | 6¼″ | 10½″ |
| 12″ | 6½″ | 5½″ | 9″ | 7¼″ | 12½″ |
Both rounds of triangles are cut a little big and trimmed. Round 1's trim size is a check: trim by the points, a quarter inch beyond each one, and the unit comes out at about that size. At 10″ the eighth inch it rounds to is a hair over the true size, so trust the points over the number there.
Before it is sewn into anything
An 8″ unit measures 8½″ before it is sewn into a block. Each point of round one sits a quarter inch from the edge, halfway along its side, and the center's four corners just touch the seams of round two. Sewn in with a quarter inch seam, round one's points land right on that seam.
Making it
1 · Cut and find the middles
Cut the center and both pairs of squares, and cut each pair once from corner to corner. Fold the center in half both ways and finger-press, and crease the middle of each triangle's long edge. That edge is on the bias: handle it by its corners.
2 · Round 1: two opposite sides
Lay a small triangle on one side of the center, right sides together, creases matched, and sew a quarter inch seam. Do the opposite side. Press toward the triangles. Trim their tips level with the center's other two sides, then add the last two the same way.
3 · Trim round 1, on point
Turn the unit so the center sits on point. Lay a ruler's quarter inch line on one corner of the center square, its 45° line along a center seam, and trim. Do all four sides. Each corner of the center now sits a quarter inch from the edge, in the middle of it; the unit measures about 6⅛″.
4 · Round 2
Match each big triangle's crease to a corner of the center square, which is the middle of a side now. Sew with the round 1 unit on top so you can see that corner, and stitch just past it into the seam allowance. Press toward the triangles, trim the tips, and add the last two the same way.
5 · Trim it to 8½″
Lay a square ruler so its 4¼″ lines run through round one's points, top to bottom and side to side, and its quarter inch lines sit on two of them. Trim those two sides, turn the unit, line the cut edges up with the 8½″ lines and trim the other two. This is the Square in a Square trim.
6 · Check it
It measures 8½″ each way. Every point of round one sits a quarter inch from the edge, halfway along its side, and the center's corners just touch round two's seams. If a center corner is cut off, round one was trimmed a little small; if it floats, a little big.
Good to know
- Why two squares cut once for round 1? It puts straight grain on round one's outside edges, which round two is sewn to, so no seam joins two stretchy edges. One square cut twice is the traditional cut, but it puts the bias on that outside.
- Pressing. Toward the triangles each round, out from the center. If the center is much darker than round one and shows through, press those seams open instead.
- Round 2 is the Square in a Square. The QuiltPlan guide for it has the same trim, step by step.
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