I was looking for unique and geeky decorations for my Halloween Party, and I’d already bought a box of Borax to make slime (I’ll also be making ectoplasm, I should note) so I did a quick internet search and discovered that, at least around Christmas, pipe cleaners and dissolved Borax make for some intriguing creations.

But what’s a snowflake got to do with Halloween? Er, nothing. So I did a little thinking and some tinkering with pipe cleaners, then went to work making my Borax crystal spider and Borax crystal ghost Cthuhlu. What? In my opinion, no good Halloween party is worth it without a little Cthuhlu. Plus, we may be cracking open Arkham Horror at some point, and the Tentacled One really needs to represent.

I’m going to be making a few more of these crystalline structures over the week and the plan is to hang them over our bar. I’ll be making mostly bones with white pipe cleaners and plan on experimenting with some other designs, as well. There are lots of versions of this particular craft online, but here’s what I did:

Borax Crystal Halloween Decorations (Spider and Ghosty Cthulhu)

You’ll need:

• Borax
• A large bowl
• A glass or plastic container (wide-mouthed is best)
• Pipe cleaners
• Pencil/chopstick
• Spoon

First, make your frame. Remember that the crystals will swell the size, so don’t make the circles/angles too tight, or they’ll grow solid. Unless that’s what you’re going for, which might be cool. Either attach a string to the finished frame or a spare pipe cleaner and then tie the end of that around a pencil or chopstick – you’ll use this to suspend the structure in the Borax solution.

Next, prepare the two containers: one for measuring out the quantity of water you’ll use and another for the actual mixing. From what I read the reason for this is to minimize crystals in the actual mixture.

Measure enough water to fill the container you’ll be using for submersion, and boil it. I used my electric kettle and it worked pretty well.

Fill the large bowl (I used a mixing bowl) with the boiling water, and start adding borax. Mix as you do this, and continue to add borax until it’s no longer dissolving. A quart of water and about 2 cups of Borax did the trick.

Slowly pour the mixture into the plastic container and be sure not to pour in any extra crystals that didn’t dissolve. Too many crystals will compete for growth later.

Submerge your frame into the Borax mixture. Try and keep the tentacles/arms from touching the sides. Mine both ended up touching and I had to pull them out, breaking the shape a little. I’ll be more careful next time.

Let the shape sit in the Borax over night, but feel free to check periodically. The crystals grow very fast, which is great for impatient geeks (like me!).

And… voila! The next morning, you’ll see a sparkly, crystal-encrusted version of your design! A very satisfying, geeky, and rather unusual Halloween decoration for your party or your house.

You can also play with food coloring and different color pipe cleaners for a variety of effects, not to mention using glow-in-the-dark paint if you want to up the spooky factor.