How to get a perfect 1/4″ seam


This, to me, is the most important aspect of making a quilt. If you don’t have a perfect 1/4″ seam, all of your measurements will be off. If you’re making a quilt from a pattern, your pieces will not line up correctly. Not a good thing!! You need perfect seams for good quilting.


I have several friends and family who are just beginning to quilt. I want them to start out correctly, and help them avoid a few of the mistakes that ended up in my “learning curve”, so I will be doing a few beginner tutorials for them, and anyone else out there who may need some guidance! (Disclaimer: This is how I do these things. There are many ways out there to quilt. These worked for me.) I will try to spell it out completely – with some general quilting hints along the way – as best I can.

Many quilters now have the option of getting a 1/4″ seam foot for their sewing machines. It’s a great investment, and if you get hooked on quilting,  you may want to get one down the road. It really takes the frustration out of sewing those seams, prevents endless “frogging” (ripping out stitches – rip-it, rip-it….get it?), and many trips to the refrigerator for beer or martini’s to calm one’s frazzled nerves. This tutorial is for those of you just starting to see if you enjoy quilting before making bigger investments!


First off, you’re going to need an index card, a stack of 6 Post-It© notes, and a few scraps of fabric, each cut exactly 2″ wide. Length doesn’t matter. I suggest 2 x 4″ pieces. Yep, that’s all you need. This isn’t rocket science and we don’t need no stinkin’ calculator or math teacher. An index card has nearly perfectly spaced 1/4″ lines!


Start by counting in two lines up from the bottom of the index card, and cutting directly ON that line, about 2/3 of the way up from the bottom of the card. Cut across, and take out that piece. You’ll end up with a card that looks like this:


Place this card under the needle in your machine. Now here’s where you need to read before you continue. It would seem easy enough – wouldn’t it? – to place that needle right on that 1/4″ mark and be on your way. Nope, probably not gonna work.


Here’s what happens if we use that blue line. IT WON’T BE AN EXACT 1/4″ SEAMLINE. Why? Because there are variables. First off, remember that I said these index card lines were nearly perfect? It means just that. There will be a little tweaking. Second, quilters actually use what is called a “scant” 1/4-inch seamline. You see, when you sew your line and open your fabric to press it, the thread and the fold actually take fabric away from the total seamline measurement. So you have to adjust your machine for that missing amount.

Trust me, all of this information IS important. It will make a difference in your quilting. I learned the hard way that it’s much easier to do it right the first time!

So, what we’re going to do instead is put the needle just to the right of that blue line that runs along the cut on the index card. Barely to the right. Use the hash marks on the top of your sewing machine to make sure the card is straight. (You know, where the 1/2″, 5/8″ lines are that you normally follow):

Do this!

We’re going to place the Post-It© notes along the first line of 1/4″ marks, measuring all the way down to make sure it’s an even 1/4″ away from that cut line. Put the sticky side of the Post-It© straight down that first line. Measure the middle and bottom to make sure they’re exactly 1/4″ away from that cut line.


Remove the index card. Now we’re going check for accuracy. Take three of your 2-inch fabric strips. Sew two strips together, butting your fabric against that sticky note line. Do not backstitch at the beginning or the end. Backstitching is not done in quilting (although some do) as it adds to the bulk of the seam.


HELPFUL HINT:  To avoid “bird nests”, or that big, knotted lump of thread that seems to form on the underside of your fabric when you start stitching, do this: Simply hold the top and bottom threads off to side, holding them down with your finger as you begin to sew. This allows you to start sewing right at the edge of the fabric.


Add the third strip to the second strip in the same manner, giving you a three-strip block (as shown in the very first picture).

Take your fabric to the ironing board. This next step is important for all the newbie quilters: PRESS THE SEAM FLAT BEFORE OPENING THE FABRIC. This “sets” the thread into the fabric. It imbeds the thread into the seamline and makes pressing it open much easier. This is also a step many quilters follow (including me) for perfectly flat seams.


Next, finger press the seams open, putting all the fabric to one side. This helps keep the fabric from stretching when you press it, as you’re “creasing” the seamline. The seam fabric is normally pressed towards the side with the darkest fabric.


Press the seams with the iron. Notice I said “press” not “iron”. “Ironing” is moving back and forth in long strokes. “Pressing” is gently laying the iron over the seam, and gently moving it down the seam, lifting the iron up-and-down. If you “iron” that block it’ll warp like a CD in a hot car. Bad. Very bad.


Note to newbies: There are two schools of thought about pressing seams open. Some (like me) always press seams to one side. Others press seams open, as you do when sewing clothing. It is purely a preference thing. For me, seams pressed to one side make it much easier to butt rows of blocks together. It is believed that seams pressed to one side are stronger. Try both and see which you prefer.

Now, measure your block. It should be EXACTLY 5-inches across. The center block should be EXACTLY 1-1/2-inches across.


Perfect! Good job! If, for some reason, you’re off a bit, go back and adjust your line again. But you should be pretty darn close. Of course, “close” only counts in horseshoes and hand grenades.

You can also use three layers of painters tape to mark your sewing line. This is how I used to do it. This way I was able to easily able change my bobbin and access the storage case in the front of my machine. Plus, it stays put better than the sticky notes.


I hope this helps you find your perfect seam line. If you have any questions, let me know!



60 thoughts on “How to get a perfect 1/4″ seam

  1. This is a great tutorial. Even though I have been quilting for years, I still refer to this test which keeps me on track. Excellent of you to share with such a precise tutorial.

    • Glad you like the tutorial, Diane. Isn’t it funny how you think you can “set it once and done”, but it never seems to work out that way? I check my seam allowance with every quilt, because you just never know!

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>