As I embarked on my quilting journey, I learned that the universal standard for all quilters is the 1/4" seam allowance. However, I didn't give much respect to this measurement. If I noticed that my seam allowance was off, I ignored it and continued with my work. My seams varied from 1/8" to 1/4" or even larger. Still, I felt proud of my imperfect quilt and didn't think it was necessary to fix these issues. But I was wrong. Sometimes, while Quilting, I faced puckering problems and later found that my seams were coming apart. That's when I realized that the 1/4" seam allowance was not just an aesthetic choice but an essential factor for the longevity of the quilt. After all, I was investing my time and energy into creating something I wanted to last for a lifetime, and ignoring the appropriate seam allowance would not work. So, let me guide you through how you can achieve the most accurate 1/4" seam allowance possible.
The 1/4" seam is easy to achieve but requires patience and practice. The proper setup of your fabric, including pressing fabric and cutting your pieces accurately, along with using 50 wt 100% cotton thread, all play a part in the accuracy of your seams. However, for now, we will focus on the stitching alone. A blog on proper pressing and cutting will come later.
Calibrating Your Machine to Achieve a Precise 1/4" Seam
I will be using the Bernina 790 Plus sewing machine to illustrate how to ensure the distance between the needle and the right edge of the pressure foot is exactly 1/4". However, since every machine and pressure foot can differ, it's best to use a seam guide to achieve accuracy. For example, even though my 1/4" foot is designed to create a 1/4" seam, it produces a larger seam, which throws off the measurements of my blocks. But it works great with my diagonal seam tape.
You can purchase multiple tools to use as a seam guide, but I will demonstrate using a plain piece of copier paper, an acrylic ruler, a pencil, and masking tape.
With your acrylic ruler, align the vertical 1/4" mark along the edge of your paper.
Trace down the ruler's edge with your pencil.
Now you have a 1/4" seam guide!!!!
Rotate your paper guide and align the right edge of your presser foot with the edge of your paper.
Move the needle position over until it is even with the 1/4" marking.
Now you are set up for sewing.
Note: On my machine, the needle position is four clicks towards the right for an accurate 1/4" needle position. I recommend that you write down your machine's accurate needle position for future reference. This will help you to easily set it up again when you are ready to sew next time.
If your sewing machine needle does not move, align the 1/4" marking with the needle and lower the presser foot.
Note: On my machine, the distance between the needle and the red notch is 1/4". I aligned the edge of my paper with the red notch and then dropped my needle.
Next, stick masking tape along the edge of the paper and attach it to your sewing tray. This tape will serve as your guide for the fabric instead of using the right edge of the pressure foot.
Testing Your Seam
Using a scrap piece of fabric, align the fabric edge with the right edge of your pressure foot. Sew a sample seam.
If using masking tape and a scrap piece of fabric, align the fabric edge with your masking tape. Sew a sample seam. I used the red notch as an additional guide for accuracy by aligning my fabric edge with the left side of the red notch.
Note: When I could no longer keep my fabric edge aligned with the masking tape, I started using the red notch as my guide. From then on, I kept my fabric edge aligned with the left side of the red notch for the rest of the sewing process.
Measure the resulting sample seam allowance with the 1/4" measurement on your acrylic ruler.
If all is right, it's time to piece some fabric together.
Practice Sewing Exact 1/4" Seams
Cut three 1 1/2" x 5" pieces of fabric.
With the right sides together, sew together two of the strips using the 1/4" seam allowance.
3. With the right sides together, sew the third strip to the first two.
4. Press the seam allowance away from the center strip or open.
5. From the right side of the fabric, measure the width of the middle strip. If it measures 1", then your seams are 1/4"!
If the middle strip is not 1", your seams were not 1/4". If it's larger than 1", then you were less than 1/4", and if it's smaller than 1", you were larger than 1/4".
Continue practicing until you achieve an accurate 1/4" seam.
I hope this blog helps you achieve accurate 1/4" seam allowances. Precise seam allowances not only provide the aesthetics we crave but also ensure the longevity of our quilts.
Happy Quilting,
Amber Foret