How to trim a quilt before binding

Hello friends and fellow quilters! Today we continue our primer on quilt binding techniques.  This lesson is on how to trim a quilt before you bind it.  I know that I am dragging you through a lot of preparatory information, and it’s been a lot to wade through. But I believe that in the long run, we are much better quilters when armed with the details. Be warned: there will be a lot of detail in this post as well. I’ve inserted a few photos here and there, but instead of inserting a photo after every step, I’m opting to insert a slideshow at the end section of the post.

What we know so far:

Up to this point, we’ve learned about the different types of binding strip cuts. We’ve learned how wide to cut binding strips. I’ve shown how to calculate how much binding and fabric you need. And finally, how to attach the strips together to create “french fold” binding.  If you’re just now finding me and want to “catch up” on those lessons, you can find Part 1 of the Primer here and Part 2 of the Primer here.

Let’s trim a quilt!

There are several ways to do this. I explain and demonstrate my favorite technique below, but there are other techniques if you want to hunt them down on the internet. (Side rant: Are you beginning to see a pattern here?  Yep, there just isn’t any ONE WAY to attack most quilting tasks. Just as there are lots of ways to skin a cat, you can prep your quilt several ways, too.) At the end of this post is a quick slideshow with visuals.  If anything isn’t clear, feel free to leave a question in the comments or shoot me an email from my contact page.

The demo quilt

The quilt I’m prepping in the photos is my version of  “Starfall” by Fresh Lemons quilt, and you can find her pattern via this link. It’s a fun quilt to make because there is so much variety in the patchwork. I love sampler quilts because they are never boring to me, and it’s a great skill builder to try blocks you’ve not made before.

The lovely custom quilting was stitched by the very talented Mary Covey. I’m lucky to know Mary and benefit from her vast experience and quilting knowledge.

After my quilt is quilted, I trim the excess batting and fabric from each side. Sounds simple enough, right? But better results are in the details, so here we go:

Gather Your “Trim a Quilt” Tools

You need the following tools:

Photo of Tools needed to trim a quilt to prepare it for binding
Tools for trimming a quilt to prepare it for binding

Of course, if you are binding a smaller quilt, you should adjust the size of your rulers to fit the project.  If the quilt is 24″ by 30″ then you could use a 8.5″ square-up ruler, and your longer ruler could be 10-15″.  For quilts that are lap size and up, I like to use a ruler that is 6.5″ x  24″ and I often pair it with my 15.5″ square-up ruler.

A word about my mat:  For this task I use an old mat.  My “good” mat is reserved for fabric cutting only. I recommend that once you are ready to retire a large mat that you keep it. (I store mine directly underneath my good one on my cutting table.) Anytime you cut batting or quilted items, batting fibers will get caught in the mat and are very hard to get out.  Instead of worrying about cleaning them out, I just always use an old mat for this task. This practice has the added advantage of extending the life of my “good” mat.

Closeup photo of rotary old cutting mat with embedded batting fibers
Note the batting fibers in this closeup photo of the mat

Your rotary cutter should have a fresh blade in it. Remember that you will be cutting through several layers, so a larger rotary cutter is appropriate.  I like to use my 60 mm cutter, but if you don’t have one that large, a 45 mm will do the job, too.

Spread the quilt out on the largest table you own.

Make the quilt lay as flat as possible on one end without allowing it to hang over on any of the sides. If the quilt hangs over the side, it will create some drag and pull on your quilt, potentially distorting your cuts. Position the cutting mat under one corner of the quilt, and position two sides of your square-up ruler along the corner.

Most people will tell you to trim your quilt exactly on the edge of the quilt top, but if I can, I like to scoot my ruler out about 1/16″ to 1/8″ outside the edge of the quilt top. This gives me just a tiny bit of bulk that will help fill up the binding so  I don’t get any gappy spaces. However, this isn’t always possible.  During the quilting process, some of the blocks may have edges that have pulled in.  You should thoroughly inspect all the outside edges of your quilt before making your first cut. Evaluate whether you can go outside the edge or not. It’s not a big deal if you can’t, but it’s nice if you can.

Square up those corners

One of the hallmarks of a well made quilt is having corners that are cut square (90 degrees angles). So, starting in your first corner, make sure the ruler is lined up straight with the corner.  Cut along both sides of the corner as far as your ruler allows, making sure you keep the ruler square to the quilt.

Next, without moving your square-up ruler, align the short side of your long ruler next to the square up ruler. The long edge should extend along the next section of the quilt that needs to be trimmed.  You know that everything is nice and square if the lines of your ruler are lining up with your blocks, but don’t get too freaked out if they don’t. The main focus here is to have squared up and straight edges. The initial corner cuts are used as our “standard” that all our future cuts “trued up” to.

Make sure your cutting mat is under your ruler and re-position if necessary. Once you know your long ruler is nice and straight, cut that section of the quilt. Continue in this manner until you get to the next corner.  Once you get to the corner, go back to your square-up ruler. Repeat the steps for squaring up the first corner.

Now that one side in trimmed, turn and re-position your quilt on your table. Repeat the process for each side of your quilt. After all four sides of the quilt have been trimmed, I fold it in half, and then fold it into quarters, just to see how well the edges match up. If I want to be real precise I will get out my tape measure and measure each side.

What if it’s wonky?

Love it anyway. It’s still going to be a GREAT quilt.

Unfortunately the trimming step isn’t where we make sure the quilt will be square. That happens as you are assembling the quilt and attaching the borders. If you’ve squared the blocks, and put the borders on properly then the quilt should be fairly square, and the trimming techniques used in these tutorials will give you excellent results.

But remember, if it’s a bit off, hardly anyone is going to notice except you. Unless it’s like 10″ off, and then you just pretend it was a design decision!

One last tip: Be sure to save the backing fabric you trim away from your quilt. It makes great scraps for your next scrappy project. And cheapskate that I am, I also save any sections of batting that are more than 10″ wide.

  • Align large square-up ruler to first corner of your quilt.
    Align large square-up ruler to first corner of your quilt.
  • Trim both sides of the quilt using the Square-up ruler
    Trim both sides of the quilt using the Square-up ruler
  • Trimming the sides of the quilt
    Align long ruler next to square-up ruler to prepare to cut the side of the quilt
  • Make the cut, then continue cutting the side, aligning part of the long ruler with a portion of a previously cut section
  • When you get to the corner, repeat all steps again for the remainder of the quilt
    When you get to the corner, repeat all steps again for the remainder of the quilt
  • Trimmed quilt ready to bind
    Trimmed quilt ready to bind
  • Usable scraps I've saved for use in another project
    Usable scraps I've saved for use in another project

I hope this lesson on how to trim a quilt has been helpful. In my next post I will walk you through how to sew binding on a quilt. I’m excited to share a super easy technique I use to hide my starting/stopping seam. And guess what?  No specialty rulers required!

If you have any questions or comments, please let me know in the comments section below. Until next time…

Happy Quilting!

Happy Quilting!