Everything you ever wanted to know about slime

The Girlguiding guide to slime - from easy DIY recipes to slimey facts to the science behind the ooey gooey gunge

Girlguiding slime team
04 May 2018

It's slime time!

We know lots of you love to make ooey, gooey, grimy slime. Whether you love it for how it feels, the sound it makes or you just love to make slimy mess, check out our guide to all things slime below. We want to hear about your adventures in slime too. Share your feats (and failures!) with us on Twitter and Facebook with #slimetime. 

Make your own Girlguiding slime

Watch our video to see what happened when we tried to make our own Girlguiding blue slime.

We used a basic recipe of cornflour and water, with a little bit of contact lens solution, to keep it simple. But if you're a slime making master and think you can do better, tell us your secrets on Twitter and Facebook with #slimetime.

  1. Start with 200 grams of cornflour in a clean bowl and a jug with 200ml of water.
  2. Add a teaspoon of bicarbonate of soda to the cornflour.
  3. Add water to the cornflour a little at a time, mixing with your hands as you go.
  4. Keep adding water until the mixture is the consistency you want. You can add more cornflour to make the slime thicker, or more water to make the slime thinner.
  5. Add a few drops of food colouring if you want to make coloured slime . Why not make it the colour of your section?
  6. Add a teaspoon of all-purpose contact lens solution and keep mixing and kneading your slime. Contact lens solution includes boric acid. Although this recipe only uses a small amount, there are health risks when using excessive amounts. You should only use a very small amount of contact lens solution and don’t make huge amounts of slime.
  7. Keep adding teaspoons of contact lens solution until the slime is the desired consistency. The more you add the more solid the slime will get.
  8. Play with the slime! Try touching the slime gently and you’ll see it behaves like a liquid and flows through your fingers. Now try applying pressure to it. If you punch it quickly you'll see the slime solidify, or try picking up the slime and rolling it into a ball.

Follow this guidance to make sure you stay safe with your slime!

  • A risk assessment should be completed if you're doing this activity with your unit.
  • Whilst the ingredients and the slime are non-toxic, they should not be ingested either before making the slime or after it has become slime - if it is consumed, seek medical advice.
  • Contact lens solution includes boric acid. Although this recipe only uses a small amount, there are health risks when using excessive amounts. Only use a very small amount of contact lens solution.
  • Rainbows and Brownies should be supervised when making slime.
  • Washing facilities should be provided and everyone should wash their hands after the activity. If any of the slime gets in their eyes, it should be carefully washed out.
  • If girls take the slime home, it should be kept safely away from younger children and animals and disposed of responsibly.
  • Check for allergies to any of the ingredients before deciding to make slime.
  • To protect clothing and furniture, especially if you’re using food colouring,  wear aprons and lay down bin bags or newspaper. Wear disposable plastic gloves to protect hands from staining.

The science behind the slime

Did you know that slime is a non-Newtonian fluid? What's a non-Newtonian fluid I hear you ask? Well, it's a fluid that's not a liquid or a solid. When you pick it up, it will feel like a solid but then it’ll ooze like a liquid. 

The thickness of a fluid is known as its ‘viscosity’. The more viscous a liquid, the slower it would flow – think water vs. ketchup. You can change the viscosity of slime but squeezing it, stirring it or adding pressure. When you add pressure or hit the slime, the particles squeeze together making it feel more solid.

5 slimey facts

  1. World's LARGEST slime - Back in the distant days of 2017, 12 year-old slime maestro Maddie Rae slimed her way into the Guiness Book of World Records by creating the largest slime the world had ever seen. It was a seriously heavy six tonnes. Now that's a lot of slime.
  2. World's LONGEST slime - Not to be out done, this year 10 year-old Ciela Villa stretched her way into the Guiness Book of World Records. She achieved the record for longest distance to stretch home-made slime in 30 seconds when she stretched her slime over two metres.
  3. Blennophobia - Is a fear of slime.
  4. Slime goes way back - Slime might be having a moment in the "slimelight" just now but it's history dates back to the 1920s when Nobel laureate Hermann Staudinger made new discoveries in polymer science (slime is a type of polymer). He suggested their structure was made up of repeating chain-like molecules, which is what we know today.
  5. Slime crazes through time  - The recent slime trend is just the latest in a long line. Perhaps the first real slime craze came in the 1950s with silly putty, which was a non-Newtonian liquid just like slime. That meant it could flow like a liquid, bounce like a ball or break if you applied force to it. In 1976 Mattel made the first toy that went by the name of slime, a green substance that came in a rubish bin. Since the 1980s slime has been a stalwart of kids TV too, especially on Nickledeon when guests would regularly be slimed (like our friend below).