People often use a famous trademark as a catch‑all for foam, but there are differences.

• Polystyrene is the plastic material itself. In crafts, it usually comes as expanded polystyrene (EPS), the lightweight white bead foam you see in balls, blocks, cones, and discs.
• The trademarked name typically refers to extruded polystyrene (XPS) insulation used in building, which is denser and formed differently than most craft foam shapes.

On this page, the items are polystyrene craft shapes made for decorating, modeling, and floral projects. If you’re comparing materials, it can help to look for “EPS craft foam” in the product details. That context can guide your choice, though availability and specific features vary by listing.

You’ll hear a few common names in everyday use:

• Craft foam or foam shapes when talking about balls, cones, discs, and blocks for projects.
• Foam balls, foam blocks, or foam cones when searching or describing specific shapes.
• A well‑known trademark is often used casually to mean any white foam, even though it technically refers to a different product type.

On Walmart’s site, product titles usually say “polystyrene foam” plus the shape and size (for example, balls, sheets, or cylinders). For the best results, try searching by the exact shape and dimensions you need, then use filters to narrow by pack size and quantity.

Polystyrene foam is a versatile base for many creative projects because it’s lightweight and easy to shape.

• Decor and ornaments: Holiday baubles, wreaths, centerpieces, and party props.
• School and science: Solar system models, molecule kits, and diorama structures.
• Floral arranging: Supports for artificial stems and centerpiece cores.
• Baking displays: Practice or display tiers (often called cake dummies), not for direct food contact.
• Modeling and cosplay: Forms for sculpting, carving, and building lightweight prototypes.

Product listings note size, shape, and pack counts, so you can match the foam to your project’s scale. Compatibility with paints and glues can vary, so checking the details and testing a small area first is a helpful step.

A quick plan can make selecting easier:

• Match the shape to the job: Balls for round ornaments, cones for trees, discs for bases, blocks or sheets for carving and floral.
• Check dimensions: Look at diameter, length, thickness, and pack counts to align with your project’s scale and storage space.
• Surface and density: Smooth, fine‑cell foam can take paint and vinyl decals more cleanly; coarser textures suit rustic looks or heavy coverage.
• Quantity: Classroom or event projects may benefit from multi‑packs.

Use the on‑page filters to narrow shapes and sizes, and consider store pickup or delivery options where offered to fit your timeline.

Polystyrene can react to solvents, so gentle, water‑based materials are a practical starting point.

• Paint: Use water‑based acrylics or tempera. Apply light coats, letting each layer dry. A thin craft sealer or lightweight spackle can help smooth pores before painting.
• Adhesive: Try PVA (white glue), tacky glue, or a low‑temperature glue gun. Avoid solvent‑based glues and spray paints that may melt foam.
• Prep: Test on a scrap first. Work in a ventilated area, keep heat sources away, and allow full drying time.
• Finishes: For glitter or paper, a water‑based decoupage medium can provide even coverage.

Methods can vary by product, so a small test helps set expectations.