This month our staff sewist Deborah brings us back to quilting basics with one of the single most important aspects of quilting: sewing that accurate quarter inch seam. Here's a link to the tutorial on our Tutorials Section for bookmarking. For those of you experienced quilters, do you have other tips or tricks for quarter inch accuracy?
How to Sew an Accurate Quarter Inch Seam
by Deborah
Sewing an accurate 1/4” seam allowance throughout your quilt
construction is essential so that all pieces will fit together properly.
First, select a seam guide and then test it for accuracy. The guide
lines on the throat plate are not always accurate, so do not trust these
measurements without testing first. Even a slight deviation will
multiply with the number of pieces sewn together to make a quilt top.
Choosing a Seam Guide
1/4” presser foot: Some machines come with this specialty foot, but if
not one is usually available to purchase. Even with this foot it is
still a good idea to test your seam allowance for accuracy, since these
feet don’t always produce an exact 1/4” seam. Some machines allow you to
move the needle position to the right or left if necessary to achieve
that perfect 1/4” seam allowance.
Adhesive: You can make your own with blue painters tape, mole skin, or use a commercial adhesive guide such as Collins Machine Seam Gauge & Adhesive Guide.
To make your own, first lower the feed dogs so that the measuring
devise will lay perfectly flat, position a piece of graph paper or a
ruler on the bed of your machine and slowly lower your needle to the
center of the 1/4” mark. Keeping your ruler straight, position the tape
along the right edge of the ruler just ahead of the needle. Remove the
ruler and test your seam allowance for accuracy by running the right
edge of your fabric up to the left edge of the seam guide. Realign if
necessary. If using painters tape, build up a ridge with three to four
layers of tape for the fabric to butt up against.
How to Test Seam Allowances for Accuracy
Cut three 1-1/2” x 4” strips of fabric. Sew the strips together
lengthwise with a 1/4” seam allowance. Press the seam allowances towards
the center strip. The center strip should now measure exactly 1”. If it
does not you will need to adjust your guide and retest again. Be
patient; it will pay off in the end!




Jul 22, 2011 at 10:06 AM So glad to hear it, Jean! It is frustrating when a quilt doesn't come out to size.
Jul 22, 2011 at 10:03 AM Thank you for this valuable information. Using the gauge on my machine, made my first machine sewn quilt smaller than graphed. Frustrated, I had to add a 2" strip around the edges. I followed your instruction, realizing my machine gauge isn't accurate. You've eliminated my animosity and inspired me to create another quilt. Thank You,