Ingredients explained
Slime Ingredients: What Does Each One Do?
Glue, activator, baking soda, water, shaving cream, clay, instant snow, cornstarch, colors, glitter: what each slime ingredient does and what to swap it with.
A glue slime relies on two must-have ingredients: glue, which provides the material, and the activator, which turns it into slime. Everything else (water, baking soda, shaving cream, clay, glitter…) adjusts the texture or adds decoration. Once you understand what each one does, you know why a recipe fails, and how to adapt it with what you have at home.
The two must-haves
PVA glue
This is the white or clear washable “school glue.” It contains long chains of molecules (a polymer: polyvinyl acetate and polyvinyl alcohol) that link up with one another. Without it, there’s no stretchy slime. Glue sticks, super glue and wallpaper paste don’t work. Everything is explained on our glue page.
The activator
This is what makes the glue “set”: it brings borate ions that link the glue chains together, like bridges. On this site, the activator is contact lens solution (saline solution) whose label lists boric acid and sodium borate, because it’s easy to find just about everywhere. There’s no boron-free activator for glue slimes. Learn all about it and compare activators on the activator page.
Ingredients that adjust the texture
| Ingredient | What it does | What to swap it with |
|---|---|---|
| Water | Makes slime softer and stretchier; without water, it’s thicker (more like putty). | Nothing: you can only use less. |
| Baking soda | It doesn’t activate on its own: it adjusts the acidity of the mix so the contact lens solution works, and it firms up the slime. | A must with contact lens solution. Don’t use baking powder instead. |
| Shaving cream | Adds thousands of air bubbles for a puffy, light slime (fluffy). | No shaving gel: it doesn’t foam the same way. |
| Soft air-dry clay | Breaks up the stretch: the slime spreads like butter (butter slime). | No oven-bake polymer clay: it’s too hard. |
| Instant snow powder | Grains that swell in water: the slime “snows” when you stretch it (cloud slime). | Hard to replace. |
| Cornstarch | Thickens and dries out doughs; with just water, it makes an amazing goo (no-glue slime). | Flour works in playdough, but not in no-glue slime. |
| Hand lotion | Softens a slime that’s too stiff or too dry. | A drop of plain vegetable oil. |
Decoration ingredients
| Ingredient | Tip |
|---|---|
| Food coloring | One or two drops in the liquid glue, before the activator. Too much coloring stains hands. |
| Acrylic or washable tempera paint | Gives bright, opaque colors; a small dab is enough. Choose a washable kids’ paint. |
| Glitter, confetti | Into the liquid glue, or they fall out. Perfect in a clear slime. |
| Fishbowl beads, foam beads | For crunchy slime. Small parts: never for kids under 3. |
| Glow-in-the-dark powder, thermochromic pigment | Magic effects, measured out by an adult (glow-in-the-dark, color-changing). |
| Scent | A flavored gelatin dessert mix (scented slime). No essential oils for kids. |
What doesn’t work
The “hacks” going around in videos often fail because they don’t provide borate ions: salt water, baking soda alone, shampoo, toothpaste or sugar water won’t make glue set. Some “2-ingredient” recipes use liquid laundry detergent, which France’s health and consumer protection authorities, ANSES and the DGCCRF, advise against. Our guide to 2-ingredient slime sorts it all out.
What about without glue?
Without glue, you don’t get a “real” polymer slime, but you can make very similar doughs: cornstarch and water, marshmallows, chia seeds, psyllium fiber, gelatin. They’re all in our borax-free slime guide.