When I first started quilting, the main thing I found most frustrating was the 1/4" seam allowance. My quilt blocks always seemed to turn out a bit to small on all sides. If you have a few quilts under your belt, you know that this will not do! A small shortage of fabric becomes a big mess in the end. I went to quilt shops and inquired about my stubborn 1/4" seam allowance. I was measuring every time and sure that my seam allowance was exactly at 1/4". I was told to use Aurifil thread or Mettler which was thin enough not to effect the seam allowance. I was told to press my seam allowances and the final quilt blocks a certain way. I took their advice but still ended up with the same result - quilt blocks slightly too small on all sides. Ugh! Then, one day a light bulb went off. I came across a blog that advised quilters to use a scant 1/4" seam allowance. This allows room for a "fold-over" allowance. In other words, the fold-over needs to be taken into consideration when sewing the seam allowance. To do this, the 1/4" seam allowance must be a thread smaller, or a scant 1/4" seam allowance so that the fold-over allowance can be added without making the quilt block too small. How do you achieve this scant 1/4" seam allowance? Follow the instructions below for quilt blocks that behave (well, most of the time):
A Scant 1/4" Seam Allowance
Formula: Scant 1/4" Seam Allowance + Fold-Over Allowance= 1/4" Seam Allowance (for quilting purposes)
- Find your exact 1/4" seam allowance on your sewing machine. With your 1/4" sewing foot, take strips of fabric and sew them together. Measure the seam allowance with a quilting ruler (I prefer Creative Grids). Is it exactly at 1/4"? If not, keep trying until you know exactly where to place the fabric on your machine so that it's 1/4" every time. You can try using index cards that have lines 1/4" apart. Place the edge of the card under the sewing foot and sew on the line. For most sewing machines, there is a notch on the sewing plate that shows where the 1/4" mark is located. I have a Bernina 330 and that notch is my exact 1/4" line. It is also where the right edge of my 1/4" sewing foot lands when in the down position.
- Now, that you've found your exact 1/4" sewing allowance on your machine, find your scant 1/4" sewing allowance. This will be much easier as all you need to do is sew a thread to the left of the exact 1/4" sewing allowance. Takes 3 strips of fabric 1-1/2" x 3-1/2". Sew them together with a scant 1/4" seam allowance. You should end up with a 3-1/2" square. If not, make your scant sewing allowance a little more or less scant. Keep practicing until you get that 3-1/2" square.
- Practice! Practice! Practice! If it's been awhile since your last quilting project, practice your scant 1/4" seam allowance with fabric scraps before using your project fabric. Keep strips of fabric 1-1/2" x 3-1/2" near your sewing machine to have on hand. You're more likely to practice before starting a new project if the strips are ready to go.