Archive for the ‘Mathematics’ Category


37.6 How Round Robins Work

May 23, 2015

This is a post describing how round robins work, or rather, how our round robin worked, complete with pictures.

If you missed a while on the blog or were redirected here from elsewhere, I was included in a multi-group internet friends (twilter-twitter quilter friend) round robin quilt exchange.

One fantastic lady, Daisy of Lazy Daisy Quilts decided to put together a round robin quilt exchange and asked for signups from interested people back at the beginning of 2014.

There were enough ladies who wanted to participate that we had 3 groups: Twilter Round Robin Group A, Twilter Round Robin Group B, Twilter Round Robin Group C. Our group was Group A

Basic Definition of a Round Robin quilt exchange:

Round Robin quilts are long-term projects in which each person works on other peoples’ projects during the time of the round robin, passing along a quilt idea, fabric, and a rapidly growing partial quilt top to each participant until the quilt ends back in the original quilter’s possession.

For me, it all started off with a pattern from electric quilt, a fabric choice & then a block.

center for round robin quilt darla

Here’s the first question I am asked when talking about the round robin: How does it work?

Generally, a round robin quilt (as our group did it) is an agreement between friends or strangers and friends to work on a quilt of someone else’s with the understanding that they will work on yours in return.

My role in the round robin:

  1. I made the center of the quilt. I decided what colors to be used & original quilt direction.
  2. I selected fabrics for the quilt to use in the quilt.
  3. I provide some kind of guidelines or suggestions to the others in the group for working on the quilt.
  4. I send the quilt onto the next person in the list (in the mail or in person). I am always sending to the same next person.
  5. I receive someone else’s quilt in the mail, with their center (or more), their fabrics, their instructions. I am always receiving a quilt from the same previous person.
  6. I work through an appropriate design to add a border to the outside of the quilt. Using math, graph paper, books or websites for inspiration, sometimes electronic quilt blocks or suggestion from Electric Quilt 7 (EQ7).
  7. I follow general guidelines by the round robin coordinator for each round to help spur imagination or direct the appropriate design. Not to be used religiously with all quilts in all situations, but to help stretch each quilter, and attempt to provide harmony with the finished project.
  8. I finish my section of the new border, sometimes making changes due to size restrictions, or fabric shortages which happens because we’re not always great at figuring out in advance what fabrics others would be appealing to the general design or just underestimation. Sometimes this step also requires purchasing fabric of our own.
  9. I write down something interesting in the process in the quilt journal. (optional) I write my name on a label provided by the original quilter (optional, but fantastically helpful in the end).
  10. I send the quilt top with my new border to the same next person in line.
  11. Receive the new quilt, repeat steps 5-10 until the original quilt comes back. I have a full quilt top and a full label and journal.

Twilter Round Robin Group A final collage


The coordinator has a lot of decisions to make before getting the round robin started.

The round robin coordinator’s role:

  1. They decide the groups (if more than 6 want to be part of the round robin) 5-6 people seem to be a good match for this round robin.
  2. They create a deadline for each border swap.
  3. The estimate the approximate amount of each type of fabric needed to make the quilt work, suggest the amount of background fabric, focus fabric, and other fabric to be used in making of a quilt top.
  4. The estimate the sizes of each of the borders to be proportional to the space on the quilt.
  5. They create general guidelines to help direct the future quiltmakers down a path to help create a good quilt and/or to ask people to work out of their own comfort zones.
  6. They coordinate the addresses and order of each person to do the round robin.
  7. They answer general questions, help figure out if deadlines need adjusted.
  8. They type up all the info and get it to the participants. Follow up if needed in some areas. Perhaps some handholding or drama-gathering if needed in some groups.
  9. Remind us it’s all fun.

Round Robin Twilter Group A

As you can see above, we had 6 different quilts with 6 different personalities and styles.

How does the passing of the quilts work?

Because we had a round that we passed quilts on to each other, and each person was in a different order, we were able to affect each quilt at a different stage of its development.

  • The first two quilts each of us received, we were only beginning to shape the look and feel of the quilt to follow.
  • The next round brought the middle into focus, the meat of the quilt,
  • The last two rounds were on the finishing side of the round, these were larger & took up more time & fabric.

Our round went like this:

Daisy passes to me, I pass to Diane, Diane pass to Laura, Laura pass to Tami, Tami pass to Tina, Tina pass to Daisy.

twilter round robin how the quilts got passed in a round

And each of us had our own version of that. The drawing above shows how the quilts were passed around.

My role in the round robin Group A, and the quilts as I saw them in the order I worked on them

Round 1 – Daisy

Since Daisy’s was the first round robin quilt I saw, it was the first one I worked on, and thus the smallest round to do.

This is a collage of the completed quilt of Daisy’s (on the left), the block as I received it, and the block as I finished it.

daisys finished quilt center and my portion

Once completed, I wrote in the journal, and on the label, then sent it in the mail to Diane.

Once Daisy was finished with the next quilt – Tina’s quilt, she sent it in the mail to me. As you will see I was always receiving from Daisy and sending to Diane. So I really only had to have 1 address.

Round 2 – Tina

Tina’s quilt only had her center and Daisy’s first border. The sky was the limit here.

tinas finished quilt center and my portion

The picture above is Tina’s finished quilt on the left. Top right is the original block, middle right is the quilt top as I received it, bottom right is the quilt top I sent out.

Round 3 – Tami

At the “halfway point” everyone was working on the opposite person’s quilt. I was working on Tami’s quilt when she was working on mine.

tamis finished quilt center and my portion


The picture above is Tami’s finished quilt on the left. Top right is the original block, middle right is the quilt top as I received it, bottom right is the quilt top I sent out.

Round 4 – Laura

Laura’s quilt was based on neutral fabrics. Greys and browns dominated the landscape of this quilt top with dramatic golds and blue hues thrown in for a smidge of color

lauras finished quilt center and my portion


The picture above is Laura’s finished quilt on the left. Top right is the original block, middle right is the quilt top as I received it, bottom right is the quilt top I sent out.

Round 5 – Diane

Diane’s quilt was mostly done. I was trying to figure out an appropriate finish for her quilt.

dianes finished quilt center and my portion


The picture above is Diane’s finished quilt on the left. Which is also the portion that I worked on and sent out to her. Top right is the original block, bottom right is the quilt top as I received it.

More notes about Round Robin Quilts & observations

Since it was a center-focused round robin where we added further borders to the outside of an already ‘finished’ project, so the projects usually take on a medallion feeling.

Each quilter has to essentially be a “border designer”, and has to be willing to either ‘do the math’ or make a program (like EQ7) do the math for them.

I used inspiration from either drawing graph paper, or Electric Quilt 7, or a book on borders, or pinterest pictures, or various books on techniques. Sometimes I tried several different versions of the quilt, but once I kept seeing one version in my mind more than 1 day, that is the variation I went with.

There is an option to do rows instead of medallion rounds, which would be the same amount of work on the last one as on the first one. This would work in a similar way, but are usually called “Row Robin” quilts instead.

The first round we received, we had a shortened timeframe, but we had less size to finish before sending it off. This was stressful for me, but I did get the quilt done by or close to the deadline most of the time.

Each swap we had different goals, different color pallets, different visions to try to work into the quilts. It is truly a good way to sew out of the comfort zone.

And since the twilters who were interested in this swap were all over the US, the boxes got some post office traveling time around the country.

Some of the early quilts I worked on, I was completely surprised with at the end.

We got to learn about each person as reading through the journal entries of the original quiltmaker, in addition to things other people said in the journal. I was inspired by things in the journal in addition to other blocks and items I saw elsewhere. Many times the journal dictated the “tone” of the quilt more than anything!

Math was very helpful in the round robin. Having the original dimensions of each quilt, then trying to figure out how to put blocks together with appropriate spacers was challenging, but a heck of a lot of fun.

It helped me to use a program like EQ7 to help with the math and to visually see if the blocks I were doing were too big or not big enough or if I needed to add spacers.

Often times, I used my moleskin graph paper the most as it was the perfect thing to visually count other parts of the quilt.

Another note was to not try to overshadow the other people’s work. Since I try to do “big bold complicated” this was a constant worry for me, and something that at times reigned me in, and other times I probably ignored. Looking back, I ended up adding a darker border many times to the quilts I received. I don’t know if/what that says about me.

The most important part is to leave a part of yourself in the quilt that you’re working on. Being true to who I am is very important to me, even if I don’t always know what that looks like. So even during the “potential overshadows” I may/maynot have done, I still made quilts that were pleasing to me, that were something that I could do as well as I could.

That’s what matters & that is what’s special about these quilts.

In summary (visual)

The quilts as I worked on them, the center block, what I did to them, and their final product.

Round Robin Progress

Yay for round robins with friends!



27.9 Little Feather Fibonacci

October 17, 2012

This last little quilt of my “three little quilt series” is a second Fibonacci quilt, made with the same green Fibonacci fabric, but this is with a different border.

I am less in love with this little border than the cute bubble border on the last Fibonacci quilt but I am leaving it, I quilted it up a little more.

This is also the quilt that on these little borders, I unquilted what I had done, and I had also learned a valuable lesson about bobbin thread.

I am going to show you backwards, the “finished quilting picture” and then move back to show the changes and details.

I call this quilt Feather Fibonacci.

Lets look at the inside fibonacci feather first.

I have been taking the class “beyond the basics” over on craftsy.  And Ann Peterson has you do a ton of feathers.

Well I watched all through the video, of them drawing the feathers, and then quilting them, and I decided the spiral arm looks like a feather spine.

I actually have drawn a couple of times some feathers on my little graph paper notebook some feathers, working out how to move from one feather to the next without always going back to the spine the way Ann does.

And after seeing some close up posts on feathers, I decided to use the method – Start one feather, branch that from the spine, connect to the first feather, then travel the tip of the 2nd feather. then branch off the feather end.

And continue in this way, feather, spine, trace over feather, feather, spine, trace over feather….

Which is an efficient way to quilt but takes some getting used to if you want plump feathers coming off instead of long skinny ones.

Not too terrible for my attempt.

Valuable lesson on this quilt #1.

You don’t have to match the backing fabric to the front, but don’t use a contrasting thread  in the bobbin from the front of the quilt.

Unless your tension is A-100% perfect and can always control your needle, that bobbin thread is going to show through.

Now I admit I wasn’t as ‘analytical’ (read the shortened version of the word) on getting the tension perfect before-hand, so I am not surprised. But I did it and kept going, even when I saw the red thread piling up on the green fabric.

Here’s the back.

Why I chose red thread for the back?  I don’t know.

Probably had more to do with the fact that I had red thread on the bobbin already and I did not have a dark blue on another bobbin.

You can see that for the pebbling practice (aka practice from Craftsy Quilting Negative Spaces with Angela Walters), I chose blue bobbin thread and this was no problem at all.

Only because I ripped out 5 pebbles that looked horrendous with red thread.

Speaking of ripping ….

Let’s talk borders.

The borders of this quilt are dark blue with lots of pattern. no issue with the red bleeding out. But I didn’t like the quilting done initially on the borders. It was my design and I did not like.

The long diamonds just didn’t work all that well for me. I couldn’t execute them well. They were sagging in the middle, and it kept feeling very ‘draggy’ making them.

So I picked them out, watching a bit more of the craftsy class. And then decided to remake them. Same design. Each one shorter Blue on both top & bottom.

Looking closely I still have some tension issues, but now I don’t notice them. And the design is tighter, it’s more coherent, and travels better down the quilt.

But it does blend in so much, it’s really providing texture rather than design.

So where do I go from here?  I think I will NOT rip out the feather despite the red thread showing through.  But I will play it up a tiny bit as intentional – provides some interest. The way I’ll do this I think is to have a very thin red line of piping around the side of the binding.

To make the binding dark blue or green (probably blue) and then a tiny bit of red, just a tiny bit, it will be interesting in color just enough, and then I can move on.

But … one issue. I’ve never done piping on a quilt before.  Next thing to learn. Although the kicker binding will give me some practice enough!


27.8 Little Fibonacci Quilt – Minimalist Style

October 15, 2012

So the 2nd quilt of my three mini quilts that I’ve been working on this past week is one quilt in a set of 2.
I took a motif that I loved in a fabric that I really didn’t own a ton of.  I cut up the large portion of the motif and made a mini quilt out of it.

Then I framed the quilt.  I used little borders of coordinating fabrics that I thought I would like in a polka-dot apron.  You can tell these fabrics are part of a set.

I quilted this minimally.

Currently you can see the fold line on the quilt, there is so little quilting on the quilt.

Hopefully for this quilt, the minimal style quilting will win out in the end. The next one, quite similar, is much more heavily quilted.

Here’s a close up of the curve.

This is obviously a quilt where the design influenced the quilting style.  I could make one more spiral a little ways out from the fibonacci curve, but I want this to be simple, simple.

So I decided to do one quick little decorative stitch, all while I had my quilting foot on the machine.  Key is to go steady and you’ll be fine.

This quilt taught me to “hold back” and “go steady.  And that you can still quilt decorative stitches with the darning foot. And it’s simple and I just like it.

Which is all a quilt ever really needs to be. Something somebody liked at one time!

Currently the fabric you see on the back, an olive green with the same dot family, is on tap to be the binding on this quilt. I am joining the binding straight edge, so I’ll see what that process is like since I’m really not all “that experienced” on binding.

And I am considering doing a blog post and/or podcast on TaDa Triangles and kicker bindings since people have been curious about both of those items based off my last podcast.

But before that, the more heavily quilted partner to this quilt, the Feather Fibonacci (to be shown at a later date).


25.1 SQ Ep 041 – Samurai Sudoku Quilt

April 22, 2012

Podcast Feed

Classic Sudoku and Quilts

You ever heard of a Sudoku quilt before?

Sudoku is a puzzle game, much in the style of magic square type of math game.

Each section of the Sudoku puzzle is it’s own little nine patch, (a 3 x 3 grid) with each box of the nine patch has a number from 1 to 9 in it.

There are traditionally nine sections in a Sudoku puzzle, each section is laid out in it’s own nine patch box. A 3 x 3 grid of sections.

Traditionally, the rule for the puzzle is as follows.

Each box in each section has a number 1-9, with no repeats.

Each box in each row (of three sections) has a number 1-9, with no repeats.

Each box in each column (of three sections) has a number 1-9, with no repeats.

Here is a picture of a printed Sudoku puzzle that is not filled out.

You can easily see the shape of the traditional (classic) sudoku pattern as a series of three nine patch blocks in three rows. A nine patch of nine patches. (fractal for those of us math nerds)

You can see some designs in how and which numbers are included with the puzzle as well.

Well, a while ago, some quilter got it in his/her head that we could use these puzzles easily in quilts. Quilts are squares, Sudoku puzzles are squares, nine patches look like Sudoku boxes.

And I’ve seen a couple of people use fabric or colors to symbolize each number.

If each of the numbers is represented by a specific color OR a specific fabric, then this turns into a very easy (just have a design wall) quilt to make. Straight stitches, nine patches. You can include sashing around the nine patches to signify the darker lines.

This quilt takes 9 of the same colors or fabrics, so you may be able to use 9 fat quarters or 9 fat eights to complete depending on the size of the quilt you want to make.

And you should be able to find Sudoku quilt patterns to purchase if you do not want to actually do the puzzle yourself. Or ask your kids (or other recipient) to do the puzzle and then give it back to you completed, and then you make a surprise quilt, including the picture of the original puzzle on the back.

Sudoku Quilt Variations Using Classic Sudoku Patterns

If you wanted to be a little different, what about setting the Sudoku quilt patches in attic windows to designate the quilt blocks?

Don’t want to do the whole puzzle? Just make the starting numbers and leave the rest blank!

Or go ahead and give them the actual numbers using applique with the method of your choice.

Here’s a link to 21 different ideas with Sudoku quilts and art!

Super Sudoku Quilts Using More Complicated Sudoku-Based Puzzles

  • Samurai Sudoku

Samurai Sudoku is a set of 5 Sudoku puzzles superimposed onto each other.

There are 5 puzzles next to each other that overlap in four areas.

The image below I haven’t put the time into getting the correct colors into the correct locations, but this is just an image that shows how the Samurai Sudoku quilt would appear.

If you’re having a hard time finding the overlapping sections, you could always use sashing colors to designate the different puzzles.

To get your own puzzle, you can look at Just look through the archive until you find an easy pattern and try it on your own. You can always download the solutions.

Also another good Sudoku reference for puzzles of all kinds (including the original and the next ones) that you can print the incomplete puzzle or the solution to the puzzle.

For making a quilt of this kind, you need 41 of the same colors for the blocks for this quilt.

If we use 2 inches finished as the size of your squares inside the block, then the quilt pictured above is 55 by 55, or if you use charm pack sized squares 4 inch finished square then the quilt can be 97 inches square.

It’s easier to upsize and downsize this quilt since it’s so simple!

  • Nonomino Puzzles

Nonomino puzzle is like Sudoku in that there are still rules of Sudoku, such as only one of each number for each row, and then one of each number for each column.

The difference is that instead of a ‘nine patch block’ shape, the blocks are irregular shaped. There are still 1-9 numbers in each block that don’t repeat.

Here is a nonomino puzzle with sashing designating the different groups available for sets of numbers 1-9.

And if I would only do the starting squares on this puzzle instead of filling it all in it would look like this:

Here’s a general sudoku puzzle site that has many variations of sudoku including nonomino and samurai styles of sudoku to try, print, and save.

Like Puzzles, Like Quilts? Send people back to this post and this podcast.


23.0 Mathematics and German

February 20, 2012

I really really want to do this pattern that I found from a link off of a link to a site in Germany. At least the website is German and also English. And the pattern is also in English.

I’ve never bought a pattern overseas before, but this would be totally worth it. But I’ve also never really used a quilt pattern before either. Not fully anyway.

The quilt that was created was located here, and I could buy the pattern here.

And I was thinking that the part that scares me the most is the buying something overseas, but I really shouldn’t worry that much, I assume it happens all the time.

I also would be taking a while to match my colors I think.

But I would be totally stoked in making this design!

Stellated icosidodekahedron

If you’re reading this when it posts, I’ll be up the road at a retreat, thinking about/sewing on my own quilts!


18.7 SQ Episode 030 – Angles in Quilting: Part C Polygons

August 21, 2011

Podcast Feed

We’re back with more angles in quilting, and we’re tackling the 5, 6, & 8 sided figures – pentagons, hexagons, & octagons respectively.

What more can be said about these blocks?


  • These blocks provide lots of challenges to piecing.  These shapes are not typically pieced the same way as triangles and quadrilaterals.
  • Account for a much smaller share of the quilting pie than triangles and quadrilaterals.
  • Think of the general ‘shape’ of the block overall due to coloring or outlining stars of specific points

Techniques used for these block colors other than piecing.

  • applique onto the background
  • set in seams (yuk say most of you)
  • english paper piecing
  • adding two blocks of smaller # of sides together to create these shapes
  • subtracting part of a square or rectangle to create these shapes
  • (foundation) paper piecing and cutting back a specific angles

Star blocks

5 sided star has 10 sides, 6 sided star has 12 sides, and you guessed it, 8 pointed block has 16 sides!

How to avoid set in seams

Adding two blocks together or subtracting from the corners of a block.


  • house block (square + rectangle)
  • cut off the top two corners of a rectangular sashing block
  • dresden plate w/ curved bottom side


  • two trapezoids (half hexagon in quiltspeak) – likely isosceles
  • 6 triangles (isosceles or equilateral)
  • weather vane piece (squished pacman block) either pieced w/ square & 2 triangles OR two parallelograms butted next to each other
  • irregular hexagon, one central triangle, and 3 triangles on the outside could be scalene, isosceles or other based on the shape
  • piece of sashing with all 4 corners removed, with the corners on the thin side meeting at a single point
  • album / autograph block – square with opposite corners removed.


  • 8 isosceles triangles together in the center (think spider web or kalidescope)
  • remove all 4 corners from a square shape with the points on no sides matching

Some quilt blocks from EQ7

Pentagons & “pentagon influenced shapes”

Hexagons & hexagon influenced shapes.

Octagons & octagon shapes.

Other things of note:

And look at my Journey Steps on the floor.  Doesn’t look big enough, does it?

Need to do more.

Also you need to go to SeamedUP and sign up to put in projects.  And encourage me to do so too!

And friend me at SeamedUP, scientificquilter. :)

Additional Resources:

Pentagon 3D shapes

Pentagon flowers (not 3D), look like GMFG, but more complicated – very pretty! where you find many different card stock weight precut polygons of all shapes.

Link to english paper piecing video (watched w/ the sound off -don’t ask why-, hope it’s helpful)

Don’t you wanna say this in text after this episode?  Here’s hoping that I remember what this means later and that I didn’t inadvertently spell something that is commonly thought of as BAD.  If so – sorry, blaming innocence here.


Send me 1 and a half inch light batik strips if you are looking to downsize your strips. (comment or

To see the first 2 podcast show notes in this series, go to Part A: Triangles, and Part B: Quadrilaterals.

Additional Music:

Mevio’s Music Alley

  • Maori King by Greg Johnson


18.3 SQ Episode 029 – Angles in Quilting: Part B Quadrilaterals

August 13, 2011

Podcast Feed

Now we’re looking at 4 sided figures in quilting – Quadrilaterals!

We have lots of kinds of Quadrilaterals from geometry class

Prallelogram Family

  • Square
  • Rectangle
  • Rhombus
    • Diamonds!
  • Parallelograms

Other Quads

  • Kite
  • Trapezoid
    • isocelese trapezoid
    • regular trapezoid
  • Random Shaped Quadrilaterals


  • all 90 degree angles
  • all equal sides
  • vertical, horizontal and diagonal symmetry
  • is a rectangle
  • is a rhombus
  • is a parallelogram
  • usually no bias edges


  • all 90 degree angles
  • opposite sides are equal length
  • opposite sides are parallel
  • vertical & horizontal symmetry
  • is a paralellogram
  • usually no bias edges

(green is squares, yellow is rectangles)


  • all equal sides
  • opposite sides are parallel
  • diagonal symmetry
  • is a parallelogram
  • potentially some bias on 2 sides usually
  • quilters call these diamonds


  • opposite sides are equal length
  • opposite sides are parallel
  • no symmetry necessarily unless special case above
  • potentially some bias on 2 sides usually


  • adjacent sides are equal length
  • opposite angles are equal
  • diagonal symmetry one direction
  • lots of bias edges
  • one definition could make a kite = a rhombus
  • one definition says that the shorter length does not equal the longer length

(dark red = parallelogram, pink = rhombus(diamond), blue = kite)


  • one set of opposite sides are parallel
  • no particular symmetry
  • cut a corner off a rectangle or square
  • created from strip sets

Isosceles Trapezoid

  • adjacent angles are equal to each other
  • one set of opposite sides are equal length
  • symmetry along one axis
  • created from strip sets and/or isosceles triangles

(trapezoid = black, both isosceles and regular)

Four sided quilt patches are everywhere!

Crossing the Streams is ‘BAD’.


If you like exploring 2D figures, and you like books, and you like podcasts, check out Flatland on CraftLit.


Ecosystem notebook from Barnes N Noble

A4 sized Grid notebook



(This is funny too, not in episode)


Mevio’s Music Alley


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