Why I HATE Scant Quarter Inch Seams!
I’m piecing our 10th block for the Friendship Quilt Along and yep, this turned into a bit of a lesson on how much I HATE scant quarter inch seams. See why this subtle difference in your piecing seam allowance can be such a pain:
Click Here to find the pattern for the Square in a Square Surprise block. I promise this block is a lot of fun to piece, so long as you use the same machine and same foot throughout the process!
I pieced half of the block on my Singer treadle and the other half on my Eversewn Sparrow 20. Unfortunately the seam allowance is not the same across both machines. The treadle has a natural scant quarter inch seam. The Eversewn with my favorite patchwork foot has a perfect quarter inch.
Of course, the type of seam you use doesn’t matter one bit when you’re piecing units like Square in a Square. Click Here to find the Square in a Square piecing tutorial. It’s when you’re combining multiple scrappy units to a larger unit that scant quarter inch seams become a major problem.
I only had three seams on the scrappy strips I was attaching to the large Square in a Square units. But just in 3 seams, the difference between a scant and real quarter inch seam is very obvious. The seam was too small, it didn’t take away enough fabric, so the resulting pieced unit was too long.
As you can see in the video, I had to do a bit of trimming in order to make the pieces fit. But once it was all put together, you would never know I had this struggle!
This is our 10th block for the Friendship Sampler Quilt Along and there are only 2-3 blocks to go. But you can join in the fun anytime, even if you find this post years after this quilt along is over. Click Here to find all the patterns and scroll down a bit on the page to find the videos too.
Let’s go quilt,
Leah Day
More Friendship Quilt Along Tutorials:
I do not like scant 1/4″seams either, and found out the hard way how being a bit off will ruin the whole quilt top layout. Being much more careful after that experience for sure.
Thank you for sharing Danice! Yep, it can definitely cause problems if you have a scrappy sashing that ends up too big and blocks that come out too small! Just thinking about scant quarter inch seams gives me a headache!
I did that with a table runner ?. Didn’t even think about it & I at 66, sewing since I was 10. Well the 2 blocks went together perfectly and the center piece, ops! Wouldn’t line up at one end. Oh well, it was a class project – totally learning…
That’s the whole point! It’s all a learning and growing process. That’s why we make quilts!
As a teacher is sewing and quilting I can say that no two machines sew the 1/4” seam the same. I always advise my students to stay with the machine they started piecing the quilt. I own two great Berninas. You would think that the 1/4” would measure the same on both with the same foot, right? But no. So when changing from one brand to another brand sewing machine they will most likely be totally different measurements. My advice stick to the machine you started with so all the seams match like they should. Great job in fixing your quilt Leah.
Thank you Jane! Yep, I definitely learned a lesson with this block. While I love piecing on my treadle machines, nothing beats a solid 1/4-inch seam allowance!
Scant quarter inches are very important if you are peicing with many seams. if you piece a 9 patch block, and expect it to fit next to a solid block, it won’t work unless you have scant quarter inch seams! One way to measure
is to cut 2 strips of fabric, 2″ wide, by 6 or 7 inches long. Press the seam and measure the width. If you do not get a full 3 1/2″, then you need to move the needle 1/2 mm toward the right {toward the cut edge}. if your machine can’t move the needle, use masking tape or painters tape to provide a new stitching line.
I disagree Marcia. As I showed in this video, I had a strip of 4 pieces fitting with a square in a square that was cut exactly to the right size. The scant quarter inch seam I used for the scrappy strips was too small, resulting in extra fabric when pieced next to the full sized units. A lot of this has to do with fabric prep and how you press the seams too, but my preference is to piece 1/4-inch seams.
OK, first off I am not a quilter even thought i have been purchasing your friendship block patterns in hopes of using some of my scraps. My question is why a scan 1/4 inch seam rather than a 1/4 inch seam? Who started it and why? Thanks for any enlightenment to this non quilter.
Great question Zoe! Scant seam allowance is nice if you press seams to one side rather than open or use very chunky thread. Thicker thread was more common and it takes up more space in the seam (fabric lost to the thickness of the thread in the seam), and then pressing to one side loses a bit of fabric too because it doesn’t flatten out quite as much as a pressed open seam. And this is still very common practice because it’s faster and easier.
So you’d piece with a scant quarter inch, which is 1 thread width less than a quarter inch. Try finding that measurement on a ruler! LOL! It’s confusing nature was part of the problem for me. I find teaching scant quarter impossible to describe or explain and it doesn’t make sense if you #1 – press seams flat which results in a flatter seam and far less fabric lost and #2 – piece with thin cotton thread like 50 wt Aurifil. The thread takes up no space and the seam ends up far flatter which means you can piece with a 1/4-inch seam and have exactly 1/4-inch taken away.
Quilting is based on math – add 1/4 inch to your pieces so that you take 1/4 inch away which leaves your pieces the right size and seam lines matching up. If you’re even 1 thread width off, when you piece very scrappy things with lots of seams, those thread widths add up quickly. If a block has 16 seams and your seam allowance is 1/16 inch off, your block will turn out 1 inch too big or 1 inch too small! So this is a nuancy kinda thing, but it has a big impact in your blocks as you can tell from the video and this explanation!
So may I ask why not just use thinner better thread and press your send open ? Why do they even use thicker thread and why not press them open please may I ask !? And dear lord I’ve been wanting to get into quilting but idk if this investment of all these rulers and things was even worth my time ! I really wanna try but this math part and the difference between machines on where it’s at and everything is so scary to me but ty I’m going to watch your video ! I was looking for a ruler or foot that really gave you this measurement but it seems every machine is off ! Crazy someone needs to invent something and they would be rich after doing so ! Lol