January Thaw Quilt Block Tutorial: 6", 9", 12", 15" and 18" finished blocks

Step by step, we'll transform the January Thaw quilt block from daunting to doable.

With a combination of traditional piecing, paper piecing, and connector corners—nothing's off-limits—you can expect your winter blues to melt away with each precise stitch as you create something truly beautiful that will last for years.

So let’s get ready to thaw out this January together – one magnificent block at a time!

With RST, match the long bias edge of C.2 to Center.1.

From the printed side, sew the seam between Center.1 and C.2 starting and ending past the outside dashed lines that surround the block.

Press.

Add C.3 in the same manner, pressing after stitching.

NOTE: When this unit is one of the larger sizes, you can add both C.2 and C.3 at the same time, then press.

Add C.4 and finally C.5.

Give the unit a good press.

Trim to size by lining up the 1/4" line on your ruler (red arrow) with the solid line. Trim away the excess to create the perfect 1/4" SA.

Repeat for the remaining three sides.

Your patches were pre-cut to ensure the outside edges of this SiaS are all on the straight of grain. That means you can remove the paper pattern now.

Press the units flat to set the seams. 

Cut each pair in half between the sewing lines.

After pressing each with SA to the darker #4, you now have 4 oversized HSTs that look something like this.

On the backside of the pair that's easiest to see your pencil line on, draw a diagonal line. Align a straight line on your ruler with the stitching (red arrow) to ensure you'll have a 90° angle in the center of your QST. 

It's possible that your drawn lines won't go exactly through the corners. It happens.

And it certainly did with mine below. That's why we cut oversized units to begin with.

Here's a close-up of the ruler position over the stitches.

With RST, pair up the marked and unmarked HSTs.

Wiggle the SA together and use pins to hold it in place as you stitch.

Press flat. Then open up each side of the sewn pairs to see if the match is to your liking. 

After it is, then cut each pair in half between the stitching.

Press the units open. 

The seam can either be pressed to one side or twirled and fanned. I chose to twirl mine as you'll see in the very last photo on this page.

All that's left is to trim our Quarter Square Triangles to size.

Using the chart below, find the 'Center' measurement for your finished block size. 

QST Dimensions
Finished Block Size	Center Measurement	Trim QST to…
6"	1¼"	2½" x 2½"
9 ''	1¾"	3½" x 3½"
12"	2¼"	4½" x 4½"
15 ''	2¾"	5½" x 5½"
18 ''	3¼"	6½" x 6½"

For our 9" finished sample, the Center is 1-3/4"—that's half the unfinished size of our QST.

At the cutting mat, position your ruler so that the Center Measurement is directly over the center of the QST, where all the seams match. (red arrow)

The dashed 45° line on the ruler is directly over the seam running upper right to lower left. 

For the upper left to lower right seam, the 'Trim QST to' size of the unit (3-1/2" for our sample) intersects that seam. 

Trim away the excess on the top and right-side exposed edges.

Flip the block 180°. (This is one of those times a rotating cutting mat is helpful!)

Match the freshly cut edges to the 'Trim QST to' size (again, 3-1/2" for our sample), the Center and dashed diagonal line are positioned just as for the first trim.

Trim away the exposed fabric and you have the perfect quarter square triangle.

Repeat for the remaining three QSTs.

We've already drawn the diagonal line on the backside of the #2 patches.

Position that marked #2, RST with a larger #1. The ends of the marked line touch two adjacent sides of #1.

Sew on the line.

Press flat to set the seam. 

Trim away the excess leaving behind a 1/4" SA. (While I always leave the #1 uncut, you can cut away the excess on that piece, too. It's a personal preference.)

Pressing for a second time, the SA is automatically towards the darker #2.

Repeat for a total of 4 units.

SAs are pressed towards the QSTs in each row to create nesting seam allowances, 

Our blocks can be a bit lumpy at the seams.

To help manage the bulky bumps, set your sewing machine to 'needle stop down'.

Sew up to the edge of the SA and stop. With the needle down through all the patches, raise your presser foot and set it back down on top of the seam. Then continue slowly stitching. 

There's less chance of your presser foot catching the edge of the SA, pushing it forward, and messing up the match.

After sewing the rows together, the finished January Thaw quilt block looks like this.

Taking a look at the back reveals our 'twirled' SAs in the QSTs and all the other pressing we did.