An Accurate ¼˝ Seam Allowance


McQ U - Accurate Quarter Inch Seam Allowance 

Use a simple sewing test to prepare your machine to sew accurate 1/4" seams. Kathy Patterson demonstrates this quick but essential step for accurate piecing. If you have problems running the video, click here for troubleshooting tips.

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Step-by-Step Instructions

Sewing with a consistent ¼" seam allowance is important in most quilting projects, and there’s more to it than just using a ¼" (patchwork) foot on your sewing machine, or sewing ¼" from the raw edges of your patches. Even if you have a ¼" foot, your seam allowances may vary. Also, when patches are opened and pressed, a bit of fabric is ˝lost˝ in the seam, which can leave you with sewn units that are slightly too small unless you take this into account when stitching. Even slight differences can significantly affect your results in a project with many seams.

To establish or check your ¼" seam allowance:

Use a fine, low-lint thread in both the top of your sewing machine and the bobbin (and use the same thread throughout your project.

McQ U - Accurate Quarter Inch Seam Allowance
McQ U - Accurate Quarter Inch Seam Allowance Mark ¼" from the center of the machine needle by placing layered masking tape, adhesive moleskin, or another seam guide on the machine bed.
Sew together 2 patches each 1½" wide, using the tape as your guide.
McQ U - Accurate Quarter Inch Seam Allowance
McQ U - Accurate Quarter Inch Seam Allowance Press the seam flat to ˝set˝ the stitching.
Open patches and press. McQ U - Accurate Quarter Inch Seam Allowance
McQ U - Accurate Quarter Inch Seam Allowance Measure the sewn unit. It should be exactly 2½" wide from raw edge to raw edge. If unit is wider than 2½˝, move tape a bit further away from needle and try again. If unit is narrower than 2½", move tape a bit closer to needle and try again. Repeat the test until you are consistently sewing an accurate ¼" seam.
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Painter's Tape Trick
I figured out the painter's tape trick years and years ago, all on my own, but I felt bad for "cheating" - and was even reprimanded for doing it by someone at a sewing center who saw that I had been using that technique, which made me feel even worse! I came here to figure out how everyone else gets consistently accurate quarter-inch seam allowances, & felt both relieved & validated when I saw that blue painter's tape! Just be sure you have it lined up perfectly straight and it works really well. But don't fault yourself for not always achieving perfection; it takes the joy out of the whole process. Just do your best and stay creative!
1/4 Inch seam allowance
I paid for a quilting class that never told me what you did for free. My very first quilt is so out of sorts it's crazy. I love McCall's. thank you
Accurate 1/4" Seam
This was a great help to me but the video provided sound but was like a test screen and could not see vision.


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