A Lesson in Partial Seams Piecing
The Double Star quilt block pattern is made from a hybrid of a half and quarter square triangles, and rectangles and a square. It uses four fabrics.
Skill Level: Confident beginner
AKA: Hope of Hartford
In order to piece the unit we'll use a technique known as 'partial seams' or 'puzzle piecing'. No special tools, rulers or templates are required. The patches are all rotary cut.
It's a fun little block to make that looks more complicated than it is. A couple of pins makes everything easy.
Not the Double Star pattern you were looking for?
'Double Star' is a common block name. There are many others.
The sample Double Star in this tutorial is 7-1/2" finished/8" unfinished.
All seam allowances (SA) are 1/4".
Several common abbreviations are used on this page. They are:
When you are instructed to press, first press the pieced unit flat to set the seams.
Then open the patch, pressing from the front.
The direction to press the SA is included at each step in this tutorial.
The fabric used in this tutorial was starch before cutting with a 50/50 mix of StaFlo starch liquid concentrate and water. Stiff fabric is easier to cut accurately and fingerpresses beautifully.
Best Press is a nice alternative, however the resulting fabric is 'crisp' rather than 'stiff'.
For QST units, I like to start with over-sized patches and trim to actual size after stitching.
For the patches marked with an asterisk (*) in the chart below, I added an extra 3/8" to the listed dimensions before cutting.
After stitching, I cut them down to the perfect size (there's a chart in the instructions right where you need this information.)
While the block design is colored with a light (white) background above, in the sample I chose a medium blue value for the effect that I wanted.
Choose fabrics in the colors that work best for you! You want fabrics with enough contrast so that your piecing handiwork shows!
As always, as you cut label your patches for easy identification throughout the piecing process.
Cutting Chart for a~Traditional Piecing ~
|Patch||Fabric||Qty||Finished Block Size||Sub|
|*1||BAC||1||4¼" x 4¼"||5¼" x 5¼"||6¼" x 6¼"||7¼" x 7¼"|
|*2||Med||1||4¼" x 4¼"||5¼" x 5¼"||6¼" x 6¼"||7¼" x 7¼"|
|*3||Light||2||3⅞" x 3⅞"||4⅞" x 4⅞"||5⅞" x 5⅞"||6⅞" x 6⅞"|
|4||BAC||4||2" x 3½"||2½" x 4½"||3" x 5½"||3½" x 6½"||na|
|5||Dark||1||2" x 2"||2½" x 2½"||3" x 3"||3½" x 3½"||na|
In the photo below I have not yet sub-cut the Large Star Points (yellow print) squares.
The QST units in this block are pieced from individually cut patches. The units are identical. There is no mirror imaging.
With RST, align the edges of one background triangle (#1) to one Small Petal triangle (#2). Double check the position of the patches to insure they are in the right position. Stitch.
Repeat for the three remaining pairs. To prevent sewing errors, keep the patches in the same order—the blue background fabric is always on top in the photo.
Press SA toward the darker patch. In this sample block it's toward the blue #1. If you use a lighter background fabric this may be toward #2 instead.
You're ready for the next seam.
Align the long edge of this pieced #1/#2 unit with the long edge of the Large Petal triangle (#3). Stitch.
Press SAs toward the larger triangle(#3) to reduce bulk.
If you cut your QST patches larger, like I did, you'll need to trim them to size. Use the chart below to find the needed measurements.
If you cut them exactly to size, use the chart to check your accuracy using the far right column. Make any adjustments needed.
For a refresher on trimming QST units to size, click here to review this technique in Quarter Square Triangle, Technique #1, Steps 6-7.
The center measurement for this QST in our 7-1/2" finished Double Star quilt block is 1-3/4".
|The center of the QST unit is at…||Trim QST unit to...|
|7 1/2"||1 3/4"||3 1/2"|
|10"||2 1/4"||4 1/2"|
|12 1/2"||2 3/4"||5 1/2"|
|15"||3 1/4"||6 1/2"|
After trimming/checking for accuracy and pressing, with RST add the #5 background rectangle to the QST.2 side of each QST unit as shown below.
Press. SA toward the background fabric. Repeat for the 3 remaining pairs.
To construct this block the first seam is a partial one. This is done to create an edge equal in length to the remaining units.
With RST, align the center square (#5) with the corner of the Large Petal fabric. Pin if needed. You will stitch along the long side of the QST unit for a little more than half the length of the center square.
Our stitching is between the black lines.
Press with SA towards the center square.
With RST, align the next QST unit with the edge of the Center/QST unit. Stitch.
Press. Seam allowance towards the QST.
Repeat for the third unit, pressing towards the center square.
Add the fourth. Pins were helpful to keep the layers evenly together during sewing. Press the sewn SA away from the center.
This is how the block looks from the front before pinning the last, partial seamline.
Now things can get a bit lumpy. Nothing that a few pins can't tame.
In the photo below, you can see how I've pinned to align and hold the edges. The far right pin is inserted past the original stitching line. This is to help hold things flat and out of the way.
Stitch this final bit.
Press, SA towards the center square.
This is how the block looks from the back.
Your finished Double Star Quilt Block from the front.
You've finished your Double Star quilt block and you're ready for more!
Check out our Free Quilt Block Patterns Library to find other star blocks to make your next quilt sparkle!
Check out these star quilt patterns available on Amazon.com...on the double! :D