In everyday shopping, “foam rubber” is often listed as:

• Upholstery foam or cushion foam (typically polyurethane, open-cell) for seats, benches, and padding.
• Craft foam or EVA foam (closed-cell sheets and rolls) for cosplay, art, and DIY.
• Polyethylene foam sheets (closed-cell) used for protective padding and projects.
• Acoustic foam for sound-dampening panels and small rooms.

Names tend to reflect the material and use. Checking the material type (open-cell vs. closed-cell), thickness, and dimensions on the product page can help you match the right sheet to your project.

Foam sheets are versatile for home, hobby, and DIY work:

• Seat replacement and upholstery for chairs, benches, and RVs.
• Crafts and cosplay (armor, props, masks, stencils).
• Gap filling and furniture protection to cushion edges or line drawers.
• School projects and modeling for displays, signs, and prototypes.
• Acoustic projects to help reduce reflections in small spaces.
• Packing and case inserts to cushion items during storage or transport.

As a general guide, thicker upholstery foam can offer support for seating, while thin EVA (about 1–5 mm) is handy for detailing and patterns. Closed-cell options may be preferable where moisture resistance is important.

Costs can vary across foam sheets because of:

• Density and firmness—higher-density materials often provide more support under load.
• Thickness and size—larger slabs use more material and ship in bigger packages.
• Material type—closed-cell foams, adhesive backings, or specialty finishes can add complexity.
• Production and quality controls—consistency, certifications, or tighter tolerances may influence cost.
• Convenience features—pre-cut dimensions, multipacks, or rolls can affect pricing.

Comparing material type, dimensions, and density on the product pages can help you balance expected performance with budget, since those details typically drive both feel and value.

Those thin, colorful sheets commonly used for crafts are usually:

• EVA foam (ethylene-vinyl acetate), often sold in 1–10 mm sheets or rolls.
• Craft foam or foam paper, especially in convenient classroom sizes.
• Self-adhesive foam sheets/rolls for quick lining and gap-filling projects.

They’re closed-cell, so they cut cleanly and can be layered for dimension. You’ll see options in multiple colors, finishes (including glitter styles), and thicknesses. For more structural builds, thicker sheets are often chosen, while thinner pieces work well for detail layers, decals, and templates.

Picking thickness depends on the seat style and feel you prefer:

• Chairs and benches: Many seat replacements use about 3–6 inches of upholstery foam.
• Backrests and padding: About 1–2 inches can add comfort without changing the profile much.
• Layering: Some projects use a firmer base with a thinner, softer topper for a balanced feel.
• Fit: Measure your cover and frame, and match width/length to avoid gaps.

Density and firmness matter as much as thickness; higher-density foams can feel more supportive at a given height. Reviewing the listed dimensions and material details on each product page can help you dial in a comfortable result.