Squishy and stretchy, slime has become a global craze, especially with kids. Its vibrant colours and gooey texture offer a hands-on sensory experience that sparks curiosity and creativity.
But what exactly is slime, how does it work, and why are kids so fascinated by it? Whether you’re a curious parent, a teacher, or just someone who wants to explore the science behind the gooey phenomenon, this guide will answer all your questions.
Plus, we’ll share five exciting slime recipes for kids to try and how your child can dive even deeper into the science of slime at one of our crazy, cool science camps!
What is slime?
At its simplest, slime is a gooey, stretchy substance that behaves somewhere between a liquid and a solid. Unlike regular fluids, such as water or oil, slime is what scientists call a non-Newtonian fluid. This means its viscosity (a measure of how thick liquid is) changes depending on the force applied to it. When left undisturbed, slime will slowly ooze like a liquid, but squeeze it, stretch it, or pull it quickly, and it suddenly feels firm.
Other examples of non-Newtonian fluids include ketchup, which flows more easily after a good shake, and toothpaste, a gel that stays neatly inside the tube until squeezed or brushed.
The science behind slime
One of the most fascinating things about slime is the science that makes it possible. We’ve already mentioned that it is a non-Newtonian fluid, but there’s much more going on beneath the surface, involving chemistry, polymers, and surprising reactions.
Here’s a breakdown of how slime works:
Polymers
The key to understanding slime lies in the concept of polymers. Polymers are large molecules made up of long chains of smaller, repeating units called monomers. Think of them as spaghetti strands tangled and connected in a network.
Cross-linking
When you mix glue, which contains polyvinyl acetate (PVA), with an activator like borax or saline solution, a chemical reaction occurs. The activator links the polymer chains together, thickening the mixture and forming what we recognise as slime.
This process, known as cross-linking, transforms the liquid glue into a flexible, mouldable material. The more cross-linking there is, the firmer and less stretchy the slime becomes.
The reaction is reversible too. If you add too much activator, the slime becomes rubbery and stiff. If you add too little, it stays sticky. This balance makes slime-making a great experiment in proportions and chemistry.
Reasons why kids love slime!
Slime’s popularity is no accident. It ticks many boxes when it comes to what children enjoy and benefit from in play, from sensory stimulation and creative expression to acting as a stress reliever.
1. Sensory stimulation
Slime’s squishy, stretchy, and sometimes bumpy texture makes it the perfect tactile tool to engage all senses in a soothing and enjoyable way. They can squeeze it slowly to feel the resistance, or stretch it to hear the satisfying popping sounds.
As a result, this can lead to improved focus and self-awareness, helping to regulate their responses to touch, especially for children with sensory processing challenges. By adding other materials into the mix, like beads or glitter, kids can further stimulate their sense of touch and sight, creating a richer sensory experience.
2. Strengthens fine motor skills
Manipulating slime through stretching, squeezing, rolling, and pinching it exercises the small muscles in the hands and fingers. These movements support fine motor development in children, which is essential for skills such as handwriting, cutting with scissors, and using utensils.
For younger children or those undergoing occupational therapy, slime offers a fun and motivating way to improve coordination and hand dexterity. And, because it feels more like play, children engage for more extended periods, boosting both muscle endurance and concentration in a low-pressure setting.
3. Creativity and customisation
One of the biggest reasons kids love slime is the endless opportunities for creative expression. They can choose colours, mix in glitter, beads, sequins, scents, or even small charms to invent their own unique slimes like “galaxy,” “rainbow,” “chocolate fudge,” or even fruit-scented slime.
This freedom to personalise encourages imaginative thinking and boosts confidence, as children take pride in creating something unique. It also nurtures artistic expression, critical thinking, and experimentation—all important skills in both school and life.
4. Hands-on learning
Slime-making introduces children to core scientific principles like states of matter, chemical reactions, and viscosity. For example, combining glue and activator demonstrates how liquids can transform into a solid-like substance through chemical bonding.
It’s a fantastic way to bring science alive outside the textbook, encouraging children to ask questions, make predictions, and think critically. Moreover, it teaches them about cause-and-effect relationships, alongside ratios, measurements, and fractions, when adjusting the amount of glue or activator affects the slime’s texture.
5. Stress relief
The repetitive motions of playing with slime, like squishing or slowly pulling it apart, can be deeply calming. It offers a quiet, focused activity that helps children manage stress and anxiety by promoting mindfulness—the act of being present and aware of your surroundings.
Slime play allows kids to release pent-up energy or tension in a safe, constructive way, much like a stress ball or fidget toy. The soothing texture and rhythmic movement help regulate emotions, making it especially beneficial after a busy school day or when winding down before bed.
Five simple slime recipes for kids
Created as a children’s toy called Gak in the 1970s, it was originally made from a combination of guar gum, borax, and water. Today, thanks to DIY videos and social media, slime has gone viral, with a wide range of textures, colours, and styles available for kids to play and get messy with!
Here are five slime recipes for kids that are easy, safe, and fun to make at home:
1. Classic slime
Traditional slime is typically made from white PVA glue and an activator, such as borax or contact lens solution. It’s stretchy, slightly sticky at first, and can be coloured with food dye.
Ingredients:
- 100ml PVA glue
- 1/2 tsp baking soda
- 1-2 tbsp contact lens solution (must contain boric acid or sodium borate)
- Food colouring (optional)
How to make it:
- Pour the glue into a bowl.
- Add the baking soda and mix until well combined.
- Add a few drops of food colouring.
- Slowly add contact lens solution while stirring until slime forms.
- Knead the slime with your hands until it’s no longer sticky.
2. Fluffy slime
By adding shaving foam to the classic slime recipe, you get fluffy slime. This slime is soft, airy, and lighter in texture, almost like a cloud. It’s very satisfying to squish and mould.
Ingredients:
- 100ml PVA glue
- 1/2 tsp baking soda
- 1 cup shaving foam
- 1–2 tbsp contact lens solution (must contain boric acid or sodium borate)
How to make it:
- Mix the glue and baking soda in a bowl.
- Add shaving foam and stir until fully combined.
- Slowly add contact lens solution, stirring continuously.
- Knead until a soft, fluffy texture forms and the dough resembles a slime.
3. Glitter slime
Add some sparkle! Mixing glitter into slime makes it visually exciting. Children love watching the light catch on the glitter as they stretch and fold the slime.
Ingredients:
- 100ml PVA glue
- 1/2 tsp baking soda
- 1-2 tbsp contact lens solution (must contain boric acid or sodium borate)
- Glitter (your choice of colours)
How to make it:
- Combine glue and baking soda in a bowl.
- Stir in the glitter evenly.
- Add contact lens solution slowly while stirring.
- Knead the slime until smooth and stretchy.
4. Clear slime
Made with clear glue, this slime is transparent and can be customised with small beads, sequins, or colours of your choice. It’s cool to create and perfect for sensory play!
Ingredients:
- 100ml clear PVA glue
- 1/2 tsp baking soda
- 1–2 tbsp contact lens solution (must contain boric acid or sodium borate)
- Food colouring, sequins, glitter, or small beads (optional)
How to make it:
- Pour the clear PVA glue into a bowl.
- Stir in the baking soda until fully dissolved.
- Add a few drops of food colouring or your chosen decorations if desired.
- Gradually add the contact lens solution, mixing continuously until the slime begins to form.
- Once it starts to pull away from the sides of the bowl, use your hands to knead it until smooth, stretchy, and no longer sticky.
5. Glow-in-the-dark slime
By adding glow-in-the-dark paint or powder, slime becomes a fun nighttime toy. It absorbs light during the day and glows in the dark—perfect for learning about luminescence.
Ingredients:
- 100ml PVA glue
- 1/2 tsp baking soda
- 1-2 tbsp contact lens solution
- Glow-in-the-dark paint or powder
How to make it:
- Mix glue and baking soda in a bowl.
- Add the glow-in-the-dark paint or powder and stir until evenly mixed.
- Slowly add contact lens solution while stirring.
- Knead the slime until it’s stretchy and glows when the lights are off.
Tips for safe slime-making
While slime is generally safe, especially when made with non-toxic ingredients, it’s important to follow a few safety tips:
- Always supervise young children during slime-making.
- Use non-toxic glue labelled safe for children.
- Avoid ingestion of slime or ingredients.
- Cover surfaces with a placemat or a large plastic sheet.
- Wash your hands before and after play.
- Store slime in airtight containers to keep it fresh.
- Dispose of slime in a general waste bin, not down the drain.
- If children have sensitive skin, consider wearing gloves or test a small amount first.
By following these guidelines, slime can be a safe, fun, and educational experience.
Make your own slime at a cool science camp!
If your kids want to make slime during the school holidays, we’ve got the break for you! Our Cool Science Camp combines the very best of PGL multi-activity at three of our most popular Kids’ Camp centres with cool science workshops provided by our partner Fun Science.
Explore static electricity, experiment with circuits, make the perfect slime recipe, and even build and code your very own Bristle Bot to take home – and that’s just the beginning!
Choose between our exciting locations at Marchants Hill or the Wiltshire Science Camp in Liddington. Have questions? Get in touch with a friendly member of our team today.
Want to give it a go? Try one of our 3-night specialist science camps instead, starting from just £399 or experience a full 7-night specialist adventure from £879pp
