Some of my patterns call for a “scant seam allowance”, and that may be an unfamiliar term to many people. Today, I want to explain the Scant Seam and why it is important!
I’m going to show two seams today, the “Standard,” or the normal seam that people learn to sew with, and the “Scant”, which is the most accurate seam to use when piecing your quilts. We are also going to talk about when to really pay attention to that scant seam!
A Scant Seam is a perfect 1/4″ seam. “But I have a 1/4″ foot!” you say- unfortunately, relying on just your presser foot isn’t always going to result in that perfect 1/4″ seam. I even have a little guide on the outside of my 1/4″ foot so that my fabric doesn’t accidentally stray, but I often find my seams to be just a hair too wide. When I first researched the “scant seam”, I ran across lots of fixes, like taping things to the sewing machine, adjusting your needles, buying fancy rulers and thingamajiggers. This is obviously an issue across the quilting world! But nothing is more frustrating than going through several steps of sewing little pieces into larger units, only to have it end up 1/4″ too short in the end, and you have to stretch it to fit and everything gets warped looking. SO annoying. In the beginning, you might think, “It’s only off by 1/16″, that’s no big deal.” but what if those added up? Quilting is a practice in precision sewing- every step along the way. My own personal fix for this is to sew just a thread’s width (keep in mind, you should be piecing with about 50 wt thread) away from my 1/4 line, and while it took some practice to get down, I now find it hard to NOT sew scant seams!
So, when should you use scant seams? The answer is: always. But most importantly, when you are sewing things like Flying Geese, or HSTs that aren’t being trimmed very much. This is trickier, because you aren’t following the edge of your fabric, but a line marked on your fabric. To illustrate how important these scant seams are, look what happens when you use the standard seam (sew exactly on your marked line) and a scant seam (a thread’s width away).
Here I have two Flying Geese units being sewn up (2 1/2″ x 4 1/2″). On the top, we have the standard seam, following along the marked line. The bottom example uses a scant seam, and you can see the orange thread slightly on the underside (the side that will be cut off) of the same marked line. Now, for both examples, the marked line is directly down the center of the square’s diagonal, and if this were a two-dimensional world, it would be perfect. However, the fabric has to fold back, over the stitching, and lay flat again. This is why that thread’s distance makes such a big difference!
Standard: Perfectly on that drawn line.
Scant: Thread’s width away. No more!
See what happens when we trim and iron those seams? The standard seam doesn’t quite line up. It’s not that big of a difference, right? But how perfect does that scant seam look? That is still the original 2 1/2″ x 4 1/2″ no matter how you measure.
Oops! You don’t want this to be seen!
Now, once you sew on the other side of the Flying Geese the standard method, trim, and press… you have a slightly too-small unit. Let’s say you have just 4 of these units next to each other, all sewn together- your final row of Flying Geese will be 1/4″ too short! Imagine if you have more than 4… yikes.
Now, the scant Flying Geese Unit is MUCH better. Everything lines up perfectly! No worries about stretching fabric to make seams match, no frustrations about re-measuring borders or sashings or even re-doing entire units of other kinds so it all fits together.
So, keep those scant seams in mind when you are sewing with quilt patterns, like my Prairie Waltz pattern (all of them, really, but this one makes a big difference with your scant seams!), remember to sew just a thread’s width away.