Part 7: How to Sew the Perfect Quilt Block

Part 7 : Basic Quilting Guidelines: How to Sew the Perfect Quilt Block or How to Sew Seams with a 1/4th or a Scant 1/4th inch Seam Allowance

The secret to sewing the perfect block is all in the seam allowances. In quilting, the 1/4th inch seam allowance is used because it creates less bulk than the 5/8” seam, commonly used in the construction of clothing. There are a few exceptions to this rule; those include paper piecing, sewing on binding which sometimes uses a narrower or wider seam allowance and sewing Rag Quilts, which uses a ½” seam allowance. Each quilter strives to sew a consistent 1/4th inch seam allowance so that the patchwork aligns correctly.

Some patterns call for a scant 1/4th inch seam, this means sewing the seam allowance about a pencil line’s width narrower than a 1/4th inch. You may find sewing a scant 1/4th inch seam works the best for all your patchwork.

Some sewing machines come with a quarter inch foot,

img2196 quarter inch quilting foot-web

but if yours does not you can use the standard foot. However, you will need to figure out which vertical groove on the machine’s throat plate is equal to a 1/4th inch.

img 2214 needle at quater in_web

You can mark the grove by laying down a strip of drafting tape.

img2233tape at quarter inch_web

Alternatively, the fabric stores and quilt shops carry a few products for this purpose, which you can purchase.


Always keep the edges of the fabric together and even with either the quarter inch foot’s edge or the 1/4 inch vertical grove or edge of the tape.

img 2238fabric against tape_web

img 2210 fabric at edge of qt foot -mark_web

The most important thing is to test your seam allowance before you start your project. To do this:

Sew a seam

  1. Measure you seam allowance with a ruler. The seam should fall just inside the 1/4th” line of your ruler
  2. If necessary, make any needed adjustments
  3. Sew another seam, than measure again

All this may seem tedious at first, but the more you sew the more natural it will feel.

Sewing a consistent quarter inch seam will help with your accuracy in creating your quilt blocks. Accurately sewn quilt blocks fit together perfectly to create your quilt top.

Here I had to sew a project with a 3/8″ seam allowance.  I followed the step described above to get the correct seam allowance.  The pictures show the steps:

img2244 finding 3 eights seam_webimg2250Tape Placement for 3 eigths_web












img2259 sewing 3 eights seam_webimg 2262 check for accuracy_web

I will show you what this project is in the near future, until then,

Happy Sewing!