How to make yarn shelves with foam core

For years and years I’ve kept my yarn in plastic bins. You can never be 100% sure of what you have, even after opening them all up, because you can never see all of your yarn at once! It’s a truly terrible way for a yarn crafter to live. (first world problems, anyone?) Plus, hello ugly.

Luckily enough, the new house we’re renting has these amazing built-ins just off the kitchen meant for fancy china, but who needs that silliness? With its see-through doors, it’s practically begging to store yarn! Now, if you don’t have anything like this, because most people don’t, cheap book shelves will do! Check your local thrift shops first!

For the first few days, I had it like this. Better than bins, but not that great. The shelves are too deep, and yarn still gets lost in there. I saw the post from All About Ami and how she had her husband make her shelves out of corrugated plastic from Home Depot and felt inspired. Unfortunately, my Home Depot didn’t carry it in-store. :/ Off to Ace Hardware! They DID have a nice thin plastic type of thing that would have worked, and I was ready to buy it, when I suddenly remembered my foam core sheets the stupid movers didn’t put into the truck and got thrown away. I wasn’t thinking about using it for this project, but I walked over to it, and my mom who was with me, suggested I use foam core instead.

It was like angels started singing. DUH!!! Foam core works perfectly!! And it’s so much easier to cut!

So that’s how I went from the picture above, to this:

Hnnng so organized and visable!!

Let me say this now: I went about this all the wrong way. I didn’t do it right. You can see how perfect the top fits, vs the middle especially, and the bottom. I figured out how I should have done it the day after, when I started thinking about it. But that’s okay, because next time I move, I’ll easily be able to make new ones!

What I did originally was draw out the rectangle on a large cardboard box to scale (my god we have so many boxes still, moving sucks), then draw lines from the corners to the center on the opposite side and measure those. It wasn’t terribly accurate, but as you can see, it worked well enough! It’s highly functional!! The bottom two shelves I ended up putting white duct tape in strategic and invisible places to make them more stable. :P

Now, you still want to draw it out, but you don’t need to make it to scale by any means. Just use the good ole’ pythagorean theorem!

I’ve included both drawings and text, so hopefully everyone can understand easily how to do this!

You want to get all of your numbers done before you go out and buy foam core, so you can be sure to get enough. Because nothing is worse than ALMOST finishing, argh!


  • Foam core [edit from the future, ooooooh: you can totally use cheap foam board from the dollar store]

  • Ruler (yard or meter stick probably)

  • Pencil (to mark on your foam core)

  • Box cutter with a brand new blade (needs to be super sharp to cut foam core smoothly)


Now, measure your length and width from the inside. The first shelf was 32.5 x 15 inches. What you need to do now is make squares. You want to split your available space into squares, or as close to squares as you can get. PLUS you have to think about how big you want the diamonds to be. I obviously tend to buy similar colors, so large ones are good for me. Plus you have to think about the sizes of skeins you buy. If you buy small, delicate skeins, you want smaller diamonds. But it’s mostly the space that determines the size.

these drawings are not to scale haha

So I turned my top shelf into 2 “squares” each measuring 15 x 16.25. Pretty close to a square! Now using the pythagorean theorem, I calculate the length of the pink lines to be 22.11 inches long.

I decided to make the depth (width) of my shelf 9 inches. I think it’s a good depth, some yarn is smaller, some is bigger, but it won’t allow any skeins to get pushed back into disappearingland.

Now, as you can see, there are intersection points at the half way point, so you’ll also have to cut those out.

So for my shelf, I cut 4 foam core planks. Each one is 22.11 x 9. To make the intersection, measure half of the length, which is 11.05. You want to cut in a slice that is the same thickness as your foam core, half way across the width, 4.5 inches.

After it’s cut out, it can be a little tricky to get it into the shelf, especially since you cut it perfectly to fit (especially if yours has a lip, dangit!!). ^^ But you’ll get it!

There’s the first one done! ^^ Ahhh, such perfection. It looks good even without any yarn on it! Hah!

So let me give you more examples to help out.

Here’s a large shelf that’s perfectly square. First you split it up into smaller squares. Then use pythagorean theorem to figure out the length of pink (a). So now you have 8 pink lines, but 4 of those pink lines can really just make 2 longer blue lines (b). So you would cut 4 a, and two b, b being 2 times the length of a. You would cut intersections at every a/2 inches on every plank. Got it?

Here’s an example I did of a shelf that’s 30 x 25:

Now I maybe would have 2 x 2 squares instead of 3 x 3 in real life, but I just wanted to show you guys more stuff.

Well that’s all! I hope you guys found this tutorial useful, and I hope you don’t feel intimidated! It’s really easy to do on your day off, it just takes a bit of time and patience.

Btw please reblog this, and link to this tutorial if you make it! And send me links to your finished shelves! I would love to see them!!

Here's a purdy image to use on pinterest:

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Omg Just what I want to do to my book shelf that is overflowing with yarn that I can not see what colors or weights I have thank you and your Mom.


This is awesome! I’m going to do this to Arnold china cabinet. Thank you for sharing


This is SO helpful! Just what I need to add to my overflowing yarn bookshelf. Thank you!


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