Look at the quilt above and count the triangles. You will give up somewhere past two hundred. Now count the pieces you actually cut and sew to make it: forty three.
That gap is the whole design, and it would be unfair to let you find it out halfway down a cutting list. Most of the triangles in this quilt are printed. Fabric A is a panel, and the three horizontal bands of small triangles come off the bolt that way. What you piece is the arrowhead at the end of each band, eighteen half square triangles and a handful of squares and rectangles, arranged so that the printed design appears to run off the edge of the panel and keep going.
Mosaic is a free quilt pattern by Angela Walters of Quilting Is My Therapy, published by Robert Kaufman in 2016 to show her Fragmental collection. It finishes at 55" x 58-1/2". Robert Kaufman rates it Confident Beginner, with the note "I have basic block construction down and would like to learn a new trick." The trick is the one above.
Pattern details
- Pattern name: Mosaic
- Designer: Angela Walters, Quilting Is My Therapy
- Publisher: Robert Kaufman Fabrics
- Finished size: 55" x 58-1/2"
- Size category: Throw
- Difficulty: Confident Beginner
- Technique: Panel, half square triangles
- Collection: Fragmental by Angela Walters
- Borders: None
- Price: Free to download
Download the free Mosaic quilt pattern PDF from Robert Kaufman
What the Mosaic quilt pattern actually asks you to sew
Here is the full inventory of the quilt top, counted from the cutting list.
- 3 panels, each trimmed to 18-1/2" x 43" from the two yards of Fabric A
- 36 pieced patches, twelve in each of three block units
- 4 strip segments, which join into the two brown bands between the panels
Forty three pieces. For comparison, Fractured Fragments, which Angela Walters designed from the same Fragmental collection, takes 1260. These two quilts came out of the same fabric line and sit at opposite ends of the effort scale, which makes them a useful pair to know about.
Of those 36 pieced patches, eighteen are half square triangles and the other eighteen are plain squares and rectangles. The eighteen HSTs come from nine marked squares, because the method here makes two at a time.
Three sizes of half square triangle from nine squares
The pattern uses one HST method three times at three scales. On the back of the larger square you draw a diagonal corner to corner, lay it on the matching square right sides together, sew a seam a quarter inch from each side of the drawn line, cut along the line, and press open. Two units from one pair.
- Three 7-1/2" pairs of Mango and Ash, giving six HSTs trimmed to 6-1/2"
- Three 5-1/2" pairs of Taupe and Ash, giving six HSTs trimmed to 4-1/2"
- Three 3-1/2" pairs of Mango and Ash, giving six HSTs trimmed to 2-1/2"
Every one of those gets trimmed after it is sewn, and the trimming is where the accuracy of this quilt lives. Eighteen units, three different target sizes, and a square ruler with a diagonal line on it doing all the work. If you want the method laid out properly, our guide to half square triangle methods and sizes covers the oversize-and-trim approach and why it beats cutting triangles. For a larger quilt you might reach for the magic eight method instead, though at nine pairs this one is not worth the setup.
Two things make the trimming go well. Square your fabric before you mark anything, because a diagonal drawn on a square that is not square sends the error straight into the seam. Our notes on cutting fabric accurately deal with that. And keep a fresh blade in the cutter, because a blade that skips leaves a nick on the bias edge of an HST and the bias is where it will show. We keep rotary cutter blades and quilting rulers for both jobs.
The block unit the pattern never measures
Quilt Assembly Step 1 says to make three block units and refers you to a diagram. It never tells you how big one is. That is worth working out before you start, because it is the number that tells you whether your panels came out right.
Step 3 tells you to trim the two brown strips to 55", which is the finished width of the quilt. The panel is 43" wide. So the block unit has to be 55 minus 43 plus the half inch the joining seam eats, which is 12-1/2" wide. It sits against the short end of the panel, so it is 18-1/2" tall.
The diagram bears that out in three columns, and each column comes to 18-1/2" on its own.
- Column one, 6-1/2" wide: an HST, the 6-1/2" Mango square, an HST. Three pieces at 6-1/2" with two seams is 18-1/2".
- Column two, 4-1/2" wide: an Ash square, an HST, the 2-1/2" x 4-1/2" Taupe rectangle, an HST, an Ash square. Four and a half, four and a half, two and a half, four and a half, four and a half, less four seams, is 18-1/2".
- Column three, 2-1/2" wide: a 2-1/2" x 7-1/2" Ash rectangle, two small HSTs, another 7-1/2" rectangle. Seven and a half, two and a half, two and a half, seven and a half, less three seams, is 18-1/2".
Six and a half plus four and a half plus two and a half, less two seams, is 12-1/2". It closes. Twelve pieces per unit, thirty six in the three.
Sewn together, those three columns read as one large coral arrowhead with a brown arrowhead inside it and a small coral point at the tip, pointing away from the panel. Three nested triangles at descending sizes, which is why it reads as a continuation of the printed mosaic rather than as a block stuck on the end.
The height works out the same way. Three rows at 18-1/2" lose a seam allowance where they meet the brown strips, the two strips contribute 2" each once they are sewn in, and the total lands at 58-1/2".
The instruction that is only in the diagram
Quilt Assembly Step 2 reads, in full: sew a block unit to a short end of each of the three panels. It does not say which end.
The diagrams answer it, and the answer matters. The arrowhead sits at the left on the first row, at the right on the second, and at the left again on the third. You can see it on the cover photograph and on the assembly diagram on the last page of the PDF.
Follow only the written step and you have one chance in four of landing on that arrangement. Put all three on the same side and the quilt reads as three repeated strips. Alternating them is what turns it into a design, because the eye follows the points down the quilt instead of across it.
It is a small thing to miss, and it is the kind of thing worth checking on a design wall before anything is joined.
What the Mosaic quilt pattern needs in fabric
Fabric amounts in the pattern assume 40" of usable width.
- Fabric A, the panel: 2 yards, cut into three sections and trimmed to 18-1/2" x 43" each
- Fabric B, Taupe: 1/4 yard, for three 5-1/2" squares and three 2-1/2" x 4-1/2" rectangles
- Fabric C, Mango: 1/3 yard, for three each of 7-1/2", 6-1/2" and 3-1/2" squares
- Fabric D, Ash: 1/2 yard, the background gray, for the rectangles, the 4-1/2" squares and all the HST partners
- Fabric E, Chocolate: 1/4 yard, three 2-1/2" strips for the two brown bands
- Binding: 1/2 yard, six 2-1/2" strips
- Backing: 3-3/4 yards
Fabric D is doing quiet work. It is the gray that surrounds the printed triangles on the panel, and it is also every background piece in the arrowhead. That is why the pieced section does not look bolted on. If you substitute, this is the one to match first, before you worry about the coral.
The backing is the other number to notice. At 3-3/4 yards of standard width you are piecing the back, since the quilt is 55" wide and the fabric is not. A 108" wide backing takes a single cut and no seam at all, which for a quilt this size is about 1-3/4 yards. Our guide to quilt backing works through both, and we keep wide quilt backing fabric for the version without a seam.
Before you start
Read the whole pattern first. Seam allowances are a quarter inch throughout, and seams are pressed open unless the pattern says otherwise, which matters more than usual here because the long seams between panel and block unit run the full 18-1/2" with nothing to hide behind.
Trim the three panels before you cut anything else. The 43" measurement is the one everything else is sized against, and if your panel will not give you 43" of usable width, you want to know that before the Mango is cut up.
Then lay all three rows out, with the arrowheads alternating, before you sew a single row seam.
Mosaic is free to download from Robert Kaufman at the link above. If you are after more like it, our collection of free quilt patterns has several hundred, sorted by size and by skill, and a fair number of them ask for a good deal more than forty three pieces.
