We’ve discovered a world exclusive secret ingredient to make perfect strong and stretchy clear slime, that you can pull really thin without it breaking. Here’s our recipe which uses clear PVA glue, a borax activator and the secret ingredient!

Read on to see how we did it, there’s a video to watch too, plus, of course…..find out the secret ingredient!!


This strong stretchy clear slime is easy to make!


Here at Devon Science we help kids make a lot of slime, either at a school workshop, a fun community event or a birthday party, we have literally made 1000s of pots of slime with 1000s of kids. I (chief scientist at Devon Science) experiment with different slime recipes and so I decided to try adding a new, secret ingredient – a chemical I have in the lab, one that I thought might just work….and YES! ….it produced as super strong, long lasting, stretchy & soft slime.

I first tried it using classic white PVA glue, which you can read about here, and below is the details of the secret ingredient being added to clear PVA, which makes strong stretchy clear slime that stretches sooooo thin without breaking.

My secret ingredient is….POLYOX, or polyethylene oxide.

It sounds very science-y, but it is easy to get online. We use it because it turns very gloopy in water and is good to demonstrate self-siphoning liquids. I was so glad I tried it out as it makes the slime really strong – it stretches very thin without breaking, it make bubbles effortlessly for guaranteed crackles!


Materials used

Large bowl and something to stir with
Clear PVA glue (see Lab Notes below)
Activator – I use my home-made borax solution (see Lab Notes below)
The secret ingredient – Polyox (polyethylene oxide)
Measuring spoon
Covering for table
Tub to store slime


Our method

I poured about 200ml of clear PVA glue into the bowl.

Then I added a dessert spoon of our secret ingredient, Polyox, and stirred this in for 10 minutes until it was completely dissolved.

Finally I added the Activator (borax – see Lab Notes below), a little at a time with good stirring in-between.

Once the slime started to pull away from the sides of the bowl, I knew it is ready to be kneaded in my hands. This is the messy part but you really need to feel the slime to determine if you need to add some more activator. If it feels too sticky, add a squirt of Activator. I kept kneading and squidging, and adding more Activator, until it was perfectly soft and stretchy.

With clear slime, you have to let it sit for a while, as in – a few days. This makes the bubbles that were formed during mixing, settle out. You can play with it with the bubbles – and this slime crackles really nicely, but clear slime with NO bubbles is pretty exciting when you get it out to play with!


Watch the video to see how easy it is to make:




This slime is very strong and resilient, but doesn’t lose its softness. I can pull and stretch it without it breaking, yet it feels soft and pliable. Its definitely a very strong, stretchy clear slime.


Clear Polyox Slime looks so shiny.


I can pull it membrane-thin without it breaking and make huge crackly bubbles with it. It’s long lasting too (we’re storing it in an air-tight container).


Lab notes

UK vs USA Slime
American videos on slime making make it so confusing if you’re new to slime, because they use ingredients we’ve not heard of but are readily available over there (e.g. Elmer’s Glue, Tide or Mule Borax). You can buy these items online, but they are expensive and you don’t need to bother as we have everything you need for sliming here in the UK !


PVA glue
Go for craft PVA glue. We’ve had success with craft glue from the well known UK shops, The Works and Baker Ross.


We make our own Activator using borax.  We make a weak solution 2.5% borax which is safe to use.

Borax’s scientific name is sodium tetraborate and nothing works better or is as cost effective as a solution of sodium tetraborate, and so we avoid the alternatives. For example, some recipes suggest using contact lens cleaner that contains boric acid or sodium borate (these contact lens cleaner are sometimes referred to as just “saline”), some say use a starch solution, the kind for spraying on shirts when you’re ironing them, again it needs to contain boric acid or sodium borate.


You may also have heard about safety concerns about borax? Well, if you want to use and make your own borax solution, it’s down to you to get informed about the safety issues and make a decision based on the evidence. In the UK the raw material (sodium tetraborate) is classified as TOXIC, but a weak solution like the one we use, e.g. 2.5%, is of low hazard. At Devon Science, we wear Personal Protective Equipment when making up a solution of sodium tetraborate, and we make it up away from other people. We keep the raw material out of reach of children and pregnant women. In case you were wondering, in America borax is readily available to buy in shops as a laundry supplement as it’s not classified as toxic over there!

Want more slime recipes?


Make strong, stretchy, crackle slime


Colour-changing thermochromic slime


Magnetic slime


Fluffy slime



If you tackle this activity at home you do so at your own risk. If you have as much fun as we did, feel free to share your pictures with us on Facebook.

Have fun sliming!
Bye for now


Chief Scientist at Devon Science

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