The 1/4" seam allowance (it's not uncommon to see it abbreviated in quilt patterns as SA) is standard for all types of
It's big enough to hold the patches together. Small enough to reduce bulk and save fabric.
Sewing an accurate, reliable 1/4" seam is the first step to enjoyable quilting.
With it our blocks fit together easily and finish up square. Quilting is a pleasure because they lay flat.
All because of an accurate seam allowance.
Why is it so important?
When your 1/4" is off, your blocks will never be accurate.
When quilters refer to the 1/4" seam allowance they are really talking about a "scant" 1/4".
In quilting, the seam is stitched, then pressed closed to set it and meddle the fibers of the thread into the fabric.
Finally it is opened and pressed with the seam generally towards the darker fabric.
A wee bit of the block fabric is "lost" in the "turn of the cloth" or where the fabric folds back on itself when the patches are opened.
With thicker fabrics (think flannel) more fabric is lost in this "turn of the cloth". Use an even thicker or heavier thread for stitching and even more fabric is lost.
To make up for this loss, quilters set their machines for a "scant" quarter inch seam.
Now we have to find it!
There are several handy tools and gizmos available to help you sew a perfect 1/4" seam allowance.
The edge of this specialty foot is a quarter inch away from the needle.
It is a good option for machines where you can't adjust the needle position (generally think older machine).
Notice in the photo how the feed dogs are exposed on the right side.
quilters believe they don't get enough traction with this foot because
There are several quarter inch presser feet on the market.
The "Little Foot" (shown here) is a generic clear version.
To choose the correct one for your machine, you need to know what type of shank it has.
My personal favorite.
This one looks like your standard presser foot but with a flange on the right side as you sit facing your machine. The raw edges of your patches ride along this flange as you stitch. Starch your fabric to make it even easier.
NOTE: You must be able to adjust your needle position to use it properly.
Use masking tape, moleskin or Post-It-Notes to create your personal quarter inch seam guide. Here's how.
As long as your presser foot doesn't extend beyond this quarter inch line, either moleskin or a short stack of Post-It-Notes can be used instead of the tape. Either one will create a higher fence or guide.
For machines with a drop-in bobbin, this method may be more trouble than it's worth. You'll need to re-tape every time you replace your bobbin.
If you find you are having trouble getting your ruler lined up properly to apply the moleskin or tape above, you might want to try the Perkins Dry Goods' Perfect Seam Guide.
Simply put it under your presser foot, then lower your needle into the hole on the guide.
Lower your presser foot onto the guide to hold it in place.
Add your tape or moleskin along the right side just as you did above.
UPDATE: Bonnie Hunter's new Essential Triangle Tool ruler includes a separate perfect seam guide ruler with it.
Cut three strips of fabric each 1-1/2" wide by about 4 inches.
Sew two strips together along the 4" side.
Sew the remaining strip to a 4" side.
Press the sewn unit flat to set the seam.
Now press the patch open, with all your seam allowances pressed towards the darker fabric.
Measure the finished block with your usual rotary ruler.
It should measure exactly 3-1/2" wide by about 4" long. The two outside sewn strips should measure exactly 1-1/4" wide, each, and the center strip should measure exactly 1".
If the strips are too wide, your seam allowance is too small, increase it.
If the strips are too narrow, your seam allowance is too big, reduce it.
It is crucial to having a happy and satisfying quilting experience that your seam allowance is accurate.
There is nothing more frustrating than finally having the time to work at your machine, only to find that your seam allowance was off and ALL of your stitching must be ripped out in order for things to fit together. ARGGGHHH!
Your perfect quarter inch seam allowance will change for different fabric and thread combinations. Flannel is a thicker fabric. You may need to use an even "scanter" seam allowance.
The only way you'll know for certain is to do a quick test.
Do take the time to retest for each new project. The few minutes you spend to test your seam allowance can save you hours of frustration from trying to piece patchwork that just won't go together.