How to sew set in seams (or Y seams)

Do you find yourself shying away from sewing diamonds and some triangles because you think that sewing the set in seams (or Y seams) will be too difficult and your corners will be a mess?

For many years in my quilting, I avoided anything that wasn't a straight seam, even though there were quilts I really wanted to make.

Then there came a day when I saw a picture of a quilt I really wanted to make. Then the desire to tackle the set in seams was greater than the will to avoid them.

With a little practice and some tips from a friend, I discovered that they really aren't that difficult, they just take some time. If someone figures out a way to speed sew set-in seams, that person will become the hero of quilters everywhere.

Obviously I haven't figured a speedy way to piece these out yet, but I have mastered them

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• diamond patches cut the correct size
• squares or triangles cut the correct size to fit your diamonds
• sewing machine (you can also hand sew these)
• thread
• sissors

1. 
   diamonds should be sewn together with the seam ending 1/4 inch from the center

   Whether you are adding squares, triangles or sewing diamonds, the process is the same.
   
   The first thing you need is to make sure that your stitching ends 1/4 inch away from the raw edge of the fabric where you will add the square or triangle.
   
   In the picture to the left, two diamonds have been sewn together and the seam ends 1/4 inch away from what would be the center of a star.
   
   Some quilters backstitch at the end because there will not be stitching that will cross over that seam. I generally do not, I just leave long tails on my threads.

2. 
   line up the square or triangle you will add so that the tip of your diamond extends beyond the square

   Next, take the piece that you will be adding - in this case I am adding a square - and line it up with your diamond.
   
   There should be a 1/4 inch on the square that extends beyond the seam that holds the diamonds together.

3. 
   pin carefully so your fabric doesn't stretch

   Pin along the seam line. In this picture, you can see how the tip of the diamond extends beyond the square.
   
   I pin very carefully. I think the key to successful set in seams is making sure that all of the individual patches line up and fit correctly.

4. 
   start in the center where the pieces meet

   I have found that my accuracy increases when I start at the center and sew to the outside.
   
   I also like to sew have the diamond on the top - that way I can see where the other seam ends.

5. 
   pin the second side of the square to the other diamond

   Now you are ready to attach the second side of your square.
   
   The corner of the square should like up with the second diamond (the one you will be attaching the square to).
   
   The tip of that diamond will extend beyond the end of your square, just as it did when you sewed the other side.

6. 
   this side I sew with the square on the top

   When I add this side, I will have the square on top.
   
   I can still see where the seam ends and I should place my needle to sew this side, but I won't be distracted by other stitching.

7. 
   once pressed, your seam will be flat - with careful pinning and sewing!

   Once you have sewn this seam, you are finished.
   
   Press the seam allowances toward the square or triangle you have added, and your Y seam (or set-in seam) will be flat!

Tips & Warnings

• pin carefully
• line up the diamonds with the square or triangle you are adding
• make sure your seam allowance is accurate
• press your seam allowance toward the square or triangle you just added
• careful not to stretch the edges of your diamonds. It is easy to do since these are bias edges
• when you are adding triangles to diamonds, it is even easier to stretch. You might spray some starch on the pieces, that may help keep them from stretching

Resources

• Beginner Quilting