Science

What's Inside: Silly String

The solid spray's secret sits in the solvent.
  • 01
    Find out how they make this molecular marvel.
  • 02

    Surfactant

    A hydrophobic (water-repelling) and hydrophilic (water-attracting) combo—aka detergent—that binds the molecules into a solid, silly stream.
  • 03

    Deionized Water, Solvent

    Shaking the can isn’t just fun -- it also mixes the solvent with the rest of the ingredients. Once the water and solvent evaporate outside the can, it leaves the foamy solids behind.
  • 04

    1,1,1,2,-Tetrafluoroethane

    Inside the can, this propellant is in a compressed liquid form. When you hit the nozzle to slime your enemies, the pressure drop causes the liquid to boil and vaporize, expanding and pushing the goo out.
  • 05

    Polyacrylic Resin

    This is what gives the string its structure. It forms the sturdy exoskeleton that keeps all that goo together. It’s got staying power, too: The shell will remain intact for weeks if you don’t clean it up.
  • 06

    Talc

    Without talc, the string would be all plastic skin and no body. Made up of mostly magnesium, silicon, and oxygen, this absorbent mineral provides the resin with some guts.
  • 07

    Isopropyl Alcohol, Ammonia

    If you find an old can of Silly String in the back of your closet and it still works, thank these ingredients. The alcohol prevents bugs from growing in the container, and the ammonia keeps the metal interior from corroding.
TopicsAMP Stories
Read More
What's Inside Triple-Action Mace? Chili Peppers and UV Dye
When you push the button, nitrogen shoves a pungent, debilitating cocktail out of the canister.
Chelsea Leu
What's Inside Squishy, Tasty-Looking Tide Pods?
What exactly is happening when you wash your clothes with fatty acid salts in a candylike package?
Patrick Di Justo
What's Inside a Magical Grease-Lifting Cleaner
K2r spot-lifter erases greasy stains with a delicate balance of chemicals.
Chelsea Leu
Inside the Strange Science of the Fake Meat That 'Bleeds'
Join WIRED for the deepest dive yet into the science of the Impossible Burger, the genetically engineered fake meat on a mission to upend the beef industry.
Matt Simon
What's Inside: Tear Gas
Just reading the list of chemicals (o-chlorobenzalmalononitrile?) inside a tear gas canister is enough to make a person cry.
Patrick Di Justo
Top Ray-Ban Coupon Codes for September 2026
Upgrade your frames with major savings on classic shapes, custom designs, and prescription lenses using these verified Ray-Ban discounts.
Boutayna Chokrane
Hotels.com Coupon Codes for September 2026
Unlock significant savings on hotels, resorts, and getaways with our verified Hotels.com promo codes and gift card discounts. Plan your perfect trip today!
Molly Higgins
Top Valvoline Coupons and Promo Codes for 2026
We've gathered all the top Valvoline coupons and promo codes for September 2026, including deals on full synthetic oil changes and other essential maintenance.
Kat Merck
Altra Running Promo Codes and Deals September 2026
Score big savings on Altra Running shoes with up to 50% off sale styles, 20% off select models, 10% off your first order when you sign up, plus free standard delivery on every purchase.
Boutayna Chokrane
Top Herman Miller Promo Codes: Save Up to 40% Off
Whether you’re looking for a Herman Miller promo code or discounts in their sale, here is how to save on the world's best ergonomic office furniture in September 2026.
Nena Farrell
Top Nike Promo Codes: 30% Off for September 2026
Check out our deals for Nike this September 2026, including 15% off select purchases.
Boutayna Chokrane
Top Nomad Goods Promo Codes: Get 25% Off in September 2026
Save up to 25% on Nomad Goods accessories such as Nomad phone cases, Nomad wallets, and more in September 2026.
Molly Higgins