Y Seams (Inset Seams) 101

Y Seams

What is a Y or Inset SeamIn my early quilting years, I was determined to make a Grandmothers Flower Garden quilt. Not those tiny little hexagons that my great-grandmother had pieced with 1" sides*. Mine was going to be much easier, because I was going to do it on the sewing machine. Also, I was going to make the hexies larger with a 2.5" side. So, I cut out my hexies, had a pretty yellow path between the flowers and started sewing away. I made about 30 'flowers', then decided it was time to assemble them into the quilt top.

I did not know any of the tips that I'm going to share with you. I lined up the raw edges and sewed from one end of the cut edge to the other. I did use pins, and when I came to an intersection, I put my needle down and pivoted the fabric and kept on sewing and finished the top. It was awful. Hardly any of the intersections lay flat! WHAT??? (I never did get that quilt top quilted, and I think I donated it to some charity group for them to deal with!!)

*Hexagons/Hexies are measured by the length of one side.

Y Seam examplesWhat is are Y Seams?

A Y Seam is also known as an in-set (or set-in, inset) seam. The Y-Seam occurs when three seams intersect. To sew them together, you make three separate straight seams. Mark each of the fabrics on the wrong side, at the 1/4" intersection as shown in the image.

A lot of quilters try to avoid Y seams, but really, they are pretty easy when you understand how to put them together!



Examples of patchwork using Y Seams (inset seams)

YSeams inset seamsThere are a lot of places that you will find Y seams. Some enterprising quilters have come up with methods to 'avoid' the Y seam, but I think you should embrace them.

    • - Hexagons aka Hexies
          Grandmothers Flower Garden (hexies)
    • - Parallelogram
    • - Stars
    • - Diamonds
    • - Tumbling Blocks
    • - 8 point stars



Y Seam Inset seam tipsHow to Sew a Y Seam

    • Use a marking pen or pencil to mark the 1/4" on each of the 3 pieces of fabric Use FINE SHARP pins to secure patchwork while stitching
    • Always stop stitching a few threads from the 1/4" mark
    • Backstitch a few stitches at the 1/4" mark
    • Never stitch into the seam allowance.


    The biggest take-away from sewing Y seams is to NOT stitch into the seam allowance by sewing 'dot to dot' at the 1/4" seam allowance.

Y Seams are an essential sewing skill that will free you to make just about any quilt you can imagine!

For more information:

  • This tutorial walks you through piecing an eight point stars - CLICK HERE
  • Jinny Beyer video walks you through both machine and hand piecing Y seams.

Shadywood Quilts is a full service company offering everything from longarm quilting to quilt finishing. Do you have a project that is almost finished? Grandmas blocks? T-shirts? Just let us know, we can probably help.