How to Make Slime with Borax and White Glue

Classic Slime Recipe

Possibly the best science project you can do using chemistry is making slime. It's gooey, stretchy, and fun! It's also easy to make.

01
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Gather Your Slime Materials

To make slime, all you need is borax, white glue, water, and food coloring.
To make slime, all you need is borax, white glue, water, and food coloring. Gary S Chapman, Getty Images

Slime only takes a few ingredients and a few minutes to make a batch. Follow these step-by-step written instructions or watch the video to see how to make slime. To get started, gather the following materials:

  • Water
  • White glue (like Elmer's™)
  • Borax
  • Food coloring (unless you want uncolored white slime)

Note, you can make slime using clear glue rather than white glue. This type of glue will produce a translucent slime. If you don't have borax, you can use contact lens saline solution in place of the borax solution. Saline solution contains sodium borate.

02
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Prepare the Slime Solutions

Mix the glue, water, and food coloring separately from the borax and water.
Mix the glue, water, and food coloring separately from the borax and water. Anne Helmenstine

There are two components to slime. There is a borax and water solution and a glue, water, and food coloring solution. Prepare them separately.

  • Mix 1 teaspoon borax in 1 cup of water. Stir until the borax is dissolved.
  • In a separate container, mix 1/2 cup (4 oz) white glue with 1/2 cup water. Add food coloring, if desired.

If you like, you can mix in other ingredients, such as glitter, colored foam beads, or glow powder.

The first time you make slime, it's probably a good idea to measure the ingredients so that you know what to expect. Once you have a bit of experience, feel free to vary the amounts of borax, glue, and water. You might even want to conduct an experiment to see which ingredient controls how stiff the slime is and which affects how fluid it is.

03
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Mix the Slime Solutions

When you combine the two slime solutions, the slime will immediately begin to polymerize.
When you combine the two slime solutions, the slime will immediately begin to polymerize. Anne Helmenstine

After you have dissolved the borax and diluted the glue, you are ready to combine the two solutions. Stir one slime solution into the other. Your slime will begin to polymerize immediately.

04
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Finish the Slime

Don't worry about the excess water that remains after your slime has formed.
Don't worry about the excess water that remains after your slime has formed. Anne Helmenstine

The slime will become hard to stir after you mix the borax and glue solutions. Try to mix it up as much as you can, then remove it from the bowl and finish mixing it by hand. It's okay if there is some colored water remaining in the bowl.

05
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Things to Do with Slime

Slime
Ryan likes slime. Anne Helmenstine

The slime will start out as a highly flexible polymer. You can stretch it and watch it flow. As you work it more, the slime will become stiffer and more like putty. Then you can shape it and mold it, though it will lose its shape over time. Don't eat your slime and don't leave it on surfaces that could be stained by the food coloring. Clean-up any slime residue with warm, soapy water. Bleach can remove food coloring, but may also damage surfaces.

06
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Keep Your Slime

Sam is making a smiley face with her slime, not eating it.
Sam is making a smiley face with her slime, not eating it. Slime isn't exactly toxic, but it isn't food. Anne Helmenstine

Store your slime in a sealed ziplock bag, preferably in the refrigerator. Insect pests will leave slime alone because borax is a natural pesticide, but you'll want to chill the slime to prevent mold growth if you live in an area with high mold count. The main danger to your slime is evaporation, so keep it sealed when you're not using it.

07
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Understand How Slime Works

Kids love to play with slime.
Kids love to play with slime. Gary S Chapman, Getty Images

Slime is an example of a polymer. It is made by cross-linking small molecules (subunits or mer units) to form flexible chains. Much of the space between the chains is filled by water, producing a substance that has more structure than liquid water, yet less organization than a solid.

Many types of slime are non-Newtonian fluids. What this means is that the ability to flow or viscosity is not a constant. Viscosity changes according to certain conditions. Oobleck is a good example of a kind of non-Newtonian slime. Oobleck flows like a thick liquid, yet resists flowing when squeezed or punched.

The properties of borax and glue slime may be changed by playing with the ratio between the ingredients. Try adding more borax or more glue to see the affect it has on how stretchy slime is or how thick it is. In a polymer, molecules form cross links at specific (not random) points. This means there is usually a bit of one ingredient or another left over from a recipe. Usually the excess ingredient is water. It's normal to have leftover water in a bowl when making slime.