Sashing and the Golden Ratio

Last week we began a discussion on sashing – the strips of fabric between the blocks and rows of a quilt.  This week we’re going to take it a bit further and talk about how wide to make the sashing, how sashing affects the overall look of a quilt, and how to pull off some really impressive sashing tricks.

If you’re using a quilt pattern that has sashing, the pattern will tell you how wide and long to cut your strips.  At this point, I always stop and think that on one hand, the quilt designer has put a lot of time and effort on the quilt and there are probably good reasons why the designer has come up with those particular sashing dimensions.  But on the other hand, because there is generally always the other hand I may want to change the look of the quilt to suit my tastes a little better.  So, what happens when you play around with sashing?

The first thing to consider is that the quilt’s border(s) will change.  They will either need to be larger or smaller than the pattern calls for.  And as intimidating as that factor can seem, it really is not that difficult to deal with, and we will do just that in a later blog.  Set that issue aside and let’s just zero in on the sashing.

Let’s say the pattern calls for 2 1/2-inch sashing strips, unfinished, meaning that when the strips are set into the quilt, they will measure 2-inches.  That is a decently wide sashing that can deal with pieced or non-pieced cornerstones.  It’s also wide enough that some serious quilting can go on in those sashing strips to enhance your quilt block.  Except what if you’re like me, and you’re not a fan of wide sashing?  To be honest, as I mentioned last week, my favorite way to set quilt blocks is on point with setting triangles.  But if I must sash, I tend to lean towards narrow sashing, one-inch wide, unfinished, so it sets at ½-inch.  When is narrow sashing more effective than the wider kind?

If the blocks are similar – either the same pattern or similar patterns – and your color palette is limited (my rule of thimble is three or less), a narrow sashing works well to unify the quilt.  The blocks are closer together and that narrow sashing adds a real punch to the quilt top.  Take a look at this quilt top:

My Favorite Shoo Fly

This is a pattern I came up with using Electric Quilt 8.  It’s a sweet quilt top that uses two or three colors well and the narrow sashing shows this off very effectively.   But what would happen if we used a wider sashing?  For the sake of this illustration, let’s push the sashing width to three inches.

My 2nd favorite shoo fly

In my opinion, the blocks lose their effectiveness with a wider width of sashing.  The limited color palate is no longer as appealing as it was with the narrower sashing.  If I did decide to use a wider sashing with this quilt to show off my long arming chops, I would use cornerstones to keep the quilt top pulled together.

shoo fly with cornerstones

Next question:  What are cornerstones?  They are squares the same size as the width of the vertical sashing.

row with cornerstones

They are pieced into the horizontal sashing to meet up with the corners of the blocks.  The cornerstones can be solid pieces of fabric, or they can be pieced, like tiny quilt blocks.  My personal favorite cornerstone pattern is a  nine-patch block.

quilt with 9 patch cornerstones

Pieced cornerstones are not only a great way to pull the colors together in the quilt, but they are also a great way to use up left-over scraps.

However, I do realize that that not everyone likes narrow sashing and not all quilts look good with skinny sashing.  Scrap quilts or quilts made from orphan blocks (blocks left-over from other quilts, blocks “gifted” to you from friends that decided they didn’t like them or didn’t want to finish a quilt, or other random quilt blocks) often look best with wider sashing. The wider sashing gives these blocks room to “breathe” –  there’s enough space between the blocks that even if the colors don’t exactly coordinate, the wider sashing along with some colorful border fabric will work to pull the quilt top together.  The wider sashing also gives the illusion that the blocks are kind of floating.  Sometime paired with second, darker colored fabric, the blocks will even appear to have a shadow.

My favorite excuse for using wide sashing is this:  The sashing strips can become blocks themselves.  And this opens up all kinds of possibilities for your quilt.  Remember this little quilt that we talked about earlier this year?

Quilt with pieced sashing

In my opinion, this little quilt is just wonderful.  Not only is it set on-point, it uses sashing as well as setting triangles.  And the sashing is pieced!  Three strips of fabric form the vertical sashing and some of the cornerstones are tiny nine-patches that work with the pieced sashing to form a secondary pattern on the quilt.  It’s simply wonderful planning and works so well with the quilt.

Now take a look at this quilt:

pieced cornerstones 2


The sashing is pieced so that it makes a secondary small star as the cornerstone.  These are small pieces, and the piecing must be very accurate in order for the sashing to look right.

And this quilt:

quilt with secondary blocks in sashing

When we pull out the sashing and look closely at it, the sashing actually is a quilt block.

quilt with secondary block in sashing

It forms the top part of the next row of blocks.  This is very clever and shows some advanced quilting techniques.  The piecing has to be very precise in order for the rows to look correct.  However, this is also something that couldn’t be easily done with narrow sashing – the sashing had to be wider to pull this off well.


So…where do you start when you have a stack of blocks you’re not sure what to do with?  The longer you quilt, the more your personal preferences will come into play.  I like quilts set on-point, with or without sashing.  If I am making a quilt with rows, I like skinny sashing better than wider sashing most of the time.  But I didn’t start out with those likes and dislikes.  Over a 30-year quilting span, those have become my favorites as my blocks have become smaller and smaller (I rarely make anything larger than a finished 8-inch block any longer).  However, if you’re just starting out, there’s this little equation called The Golden Ratio you may want to brush up on.

In mathematics two quantities are in the golden ratio if their ratio is the same as the ratio of their sum  to the larger of the two quantities.  It is also called the golden mean.  In geometry, it’s a bit different as the Greek letter pi represents the golden ratio.  I could go through the entire formula (and the physics teacher in me is just raring to do that), but I don’t want to lose anyone at this point.  Let’s just say Euclid and a lot of other mathematicians and scientists have spent copious amounts of time on it and the golden ratio boils down to this figure:   1.6180339887….  The number is irrational as it goes on forever, never ending.  For the sake of ease, we cut it down to 1.618.

Now I know what you’re asking.  I can see your eye roll from here…You’re asking yourself, “What in the world does this have to do with quilt blocks and sashing?”  In a nutshell, folks like architects, artists (da Vinci was a big fan of the Golden Ratio), musicians (yup, it’s used there, too) and designers have used the formula to develop pleasing designs.  Quilters have been no different.  And before you start sweating bullets over the math of this part of quilting, allow me to let you in on a little secret:  Most of the time this comes naturally to people that deal with design work and quilters fall into this category.  Let me also say here that numbers don’t lie, and you should do the math if there are any doubts.


Let’s set this scenario:  You have purchased a stack of 8 ½  blocks from an estate sale.  You know the blocks will finish to 8-inches once the sashing is sewed on.  The first thing you do is multiply 8 x 1.618 and get 13.  This does not mean your sashing is 13-inches wide.   Take 13 and divide it by 4 (for all four sides of the block) and you get 3 ¼-inches for each strip of sashing finished.  Add ½-inch to that for seam allowances you could cut your sashing strips up to 3 ¾ -inches wide.  That is the largest size sashing that would still look good with your blocks. That seems large, especially to folks like me who prefer skinny sashing.  But if you piece your sashing and have cornerstones, that’s really a great size to work with.


However, what if you just don’t want to go through all that trouble?  If you’ve purchased the blocks with the goal of setting them in a top for a charity cause or a child’s play quilt, you may not want to go through all the trouble of piecing the sashing and cornerstones.  You may just want to set the blocks in rows with sashing and move on.  In this case, you would take the finished size of the block (8-inches) and multiply it by it by roughly half the golden ratio – 8 x .618 = 5 inches.  Then 5 divided by 4 = 1 ¼ inches.  Now add ½-inch for a seam allowance and the width of the sashing should be cut is 1 ¾ – inches.


Between the two extremes – the widest sashing  being 3 ¼-inches wide and the narrowest at 1 ¼-inches wide (finished) sets the stage for all the options of the sashing width.  Your sashing can fall anywhere within these two measurements and it will look wonderful.  However, if it’s wider than 3 ¼-inches or narrower that 1 ¼-inches, it will look out of proportion.


The math isn’t hard, and the golden ratio is also used to figure border width, as well as the best width and length of the quilt center.  But if math is just not your thing, Jinny Beyer sells a wonderful tool called the Golden Gauge Calipers that takes all the math-ing out of the design work.  She has them on her website, as well as detailed instructions on how to use them.



I hope that the two blogs on sashing has helped you look at all the options out there for sashing.  I also hope you decide to “spice” your next quilt top’s sashing up a little with some pieced sashing and cornerstones.  It’s the little extra steps like these that really make a quilt top not only sing but sing in harmony!


Until next week, Quilt with Excellence!


Love and Stitches,

Sherri and Sam





Categories: Uncategorized

5 Comments on “Sashing and the Golden Ratio”

  1. July 30, 2018 at 7:23 pm #

    This is such a great informative article and I learned a lot! Thanks for writing it. I am looking forward to try the ‘sashing and cornerstones are also pieced blocks’ method. Love how complex that makes a quilt lool.

  2. Ecee Read
    September 17, 2020 at 11:22 am #

    Thanks so much that is such great information. I am a beginner and that helped me a lot. However I have one question. My block size is finished 12″ so using the golden theory my top sashing would be 2-1/2″. What about the sashing on the back what size would I make that and how do i calculate it. Ecee Read, Brantford, Ontario, Canada

    • September 17, 2020 at 12:01 pm #

      I’m not sure I know what you mean about the sashing on the back? If you could explain what you mean I’d be happy to try to answer your question.

  3. October 6, 2020 at 2:50 pm #

    I miscalculated my sashing requirements and after adding sashing to one side of all my blocks I realize I do not have enough to do the vertical rows. The fabric is discontinued. What ideas do you have for using a different or similar color in the vertical? Thank you!

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