September 14, 2016

Snowball Block: Making the Octagon

The snowball quilt block has been around for a long time. The basic block is an octagon that gives the illusion of a circle. According to a little online research, it's an Amish block. I make no claims as a quilt historian but one thing I do know is it's a wonderfully versatile block. Check out all these quilt tutorials curated by Quilt Inspiration that use a snowball block. So many variations are possible. This is the version on my design wall right now.

The easiest way to make a snowball block is with small corner squares that are stitched across the diagonal, trimmed, and then flipped open to form corner triangles. While this method uses more fabric than sewing triangles, I find it fast and easy. All you need is one big square and 4 small squares for the corners. No bias edges to contend with.

No need to let those trimmed corners go to waste either.  Once I've gotten a decent start on making the blocks and have a handful of trimmed corner triangles, I use them as leaders and enders when sewing the rest of the blocks. This way I end up with lots of half square triangles sewn and ready for a second project like a mini quilt or pillow. It's like making two projects in one. Gotta love that!

So you might be asking how do you know what size small square to use? Well, the size is often determined by the quilt setting you are using. Because a snowball block is frequently paired with another block in an alternating setting, the size of the corners is usually determined by the breakdown of the alternate block. In other words, If the alternate block is a 9-patch block, then the side of the snowball block is divided by three. If the alternate block is a 16-patch, then the side of the snowball block is divided by four. Here's a great source for determining the size of the corner squares for various sized snowball blocks.

The most common sizing for a snowball block calls for dividing the finished size of the block by three and then adding a half inch seam allowance. This would then align with a 9-patch block as shown above left. Whatever number you are dividing by you will still add 1/2" seam allowance. For my quilt the finished block size is 6" so the squares would be cut 2 1/2" x 2 1/2".  (6 divided by 3 equals 2 plus 1/2" equals 2 1/2")

Since my quilt is made entirely of snowball blocks, the size of the small corner squares didn't matter so much. The triangles didn't need to line up with any points on an alternate block, they simply line up with each other.

I started with the typical directions and made a sample block using the 2 1/2" corner squares. It didn't really seem as much like an octagon as I wanted. All eight sides of the octagon aren't the same length. Of course they'll change a little once the seam allowances are taken into account but it still wasn't going to be a true octagon. Here's what it looked like.

Wanting a more true octagon, I turned to my computer to see if I could figure out a better size for the corners. Since I didn't know the mathematical way to draw an octagon in Illustrator, I estimated using a small grid. For my finished 6" block I found that if my corner squares were cut 2 1/4" the end result was as close to a true octagon as I could get. In other words all eight sides were of equal length. You can see the difference below between the 2 1/2" square (left) and the 2 1/4" square (right). The one on the right is closer to a true equal sided octagon.

I know this is a small thing to some of you, but it was worth the effort to me. Not to mention I could get more small squares from my yardage so I needed less fabric. All together I need 900+ of the small squares so I have a lot of cutting to do.

I'll be back with another post soon showing you my quick method of sewing the corner squares without any marking. It saves a ton of time.

Until then, I'm curious, have you ever made a quilt that included snowball blocks?

I'm linking up this week to Needle and Thread Thursday at My Quilt Infatuation. It's been far too long since I've played along. Hop over and see Kelly's latest quilt finish.



  1. I think putting the effort into finding the size that makes the octagon look right was well worth it. And it is definitely extra helpful that you can get more blocks from your yardage! 900+ is lot.

  2. Interesting method to find that corner triangle block. I would have assumed it would have been a 2" measurement, as I always think of the octagon as a hidden nine-patch block. Fun to see this post!

  3. Anne, enjoyed your snowball explorations! Thanks for sharing the details!

  4. I am so loving these blocks. I have used the snowball blocks is several of my quilts.

  5. So nice, Anne! Though I think you know I'm not a fan of Kaffe fabrics, the way you've chosen to emphasize them is great. I've made several snowball block quilts, for missions to help children. The snowball is a great way to play up a focus fabric, whether it's a novelty print, or as you have done. Great work.

  6. Snowballs during our Indian summer heatwave! I like your colourful flowered snowballs, despite the heat! Thank you for the link to that snowball block information; it's much ,ore versatile than I'd realised.

  7. Thanks for sharing Anne. I have a Kaffe snowball quilt but I have yet to use the snowball as an alternate block. I will have to try that sometime. Your blocks are yummy!

  8. I just finished yet another pillow cover that uses a snowball block for the center (for my next pattern!). Don't know that I'll ever make a Kaffe snowball quilt, but it could happen someday... it's temptingly pretty.

    Have you tried the "polygon" tool in Illustrator? Just input the number of sides. Much easier than using a grid and just drag a corner to resize.

  9. I don't remember ever making a snowball block at all! But you make it very enticing Anne! Your Kaffe quilt is going to be looking wonderful!

  10. I have never made the snowball block, but it is definitely on my list. The snowball I have in mind looks more like the one you divided in four, it's great information, I am saving this and I will be looking forward to seeing the progress. Love the tiny polka dots and love all Kaffe's fabrics, it's going to be fabulous!!

  11. I really like these blocks you made, they are a great way of showcasing a focal fabric you don't want to cut up while still adding interest. Beautiful!


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