Homemade Floam

    Kids, what is like slime with polystyrene beads in it that can be molded into shapes? It’s a really fun toy called Floam™. You can sculpt with this colorful goop or use it to coat other objects. You can store it to reuse it or allow it to dry, if you want permanent creations. It's a lot of fun, but not always easy to locate. So, you can make a type of 'Floam' yourself. Like slime, it is generally safe, though anything containing food coloring can stain surfaces (don’t eat it though, because polystyrene beads simply aren't food!). 

    Please note:  All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.

    Here is what to do:

    1. Dissolve 2 tsp. borax completely in 1/2 cup water. (If you want slimier, more flexible 'Floam', then try 1 tsp. borax instead)

    2. In a separate container, mix 1/4 cup white glue and 1/4 cup water. Stir in food coloring.

    3. Pour the glue solution and about 1 1/3 cup of polystyrene beads into a Ziploc® plastic bag. Add borax solution and knead it until it's well mixed. Use 1 tbsp. of the borax solution for a very fluid Floam, 3 tbsp for average Floam, and the entire amount for stiff Floam.

    4. To keep your Floam, store it in a sealed bag in the refrigerator (this discourages mold). Otherwise, you can allow it to dry into whatever shape you chose.

    How it works:

    Borax reacts to crosslink the polyvinyl acetate molecules in the glue. This forms a flexible polymer.


    1. If you use a 4% solution of polyvinyl alcohol instead of glue, you will get a more transparent product that will hold shapes better.

    2. Polystyrene beads can be found at craft stores (e.g., JoAnn Fabrics), usually as fillers for bean bags or dolls. Or, for more hands on fun, you can grind Styrofoam™ cups using a cheese grater. 


    Kathleen Carrado Gregar, PhD, Argonne National Labs
    May 2007



    Anne Marie Helmenstine’s “About Chemistry” at