Foamma Upholstery Foam Blocks 4" x 20" x 20" — 4-Pack High-Density 4" Thick Cushion Inserts, CertiPUR-US

Foamma's 4" x 20" x 20" high-density upholstery foam pads are firm, resilient cushion inserts designed to restore seating comfort and structure for chairs, sofas, and DIY upholstery projects.

These pre-cut foam blocks arrive as a convenient four-pack sized for small to medium cushions, replacement seat cores, craft uses, and repairs. Manufactured in the USA and CertiPUR-US certified, the foam balances lasting support with low emissions. Each block is simple to trim or layer for a tailored fit and slips into covers or frames for fast refurbishment of worn seating or new handmade cushions.

How will these foam blocks perform for everyday seating?

The high-density formulation resists sagging and offers firm support for frequently used seats. They maintain shape through repeated sit-stand cycles and recover quickly after compression, making them suitable for dining chairs, occasional armchairs, bench seating, and tight sofa cushions.

• Firm, high-density core engineered for durability and shape retention
• 4-inch thickness provides noticeable lift and seating support
• Pre-cut 20" x 20" footprint fits many standard cushion covers
• Works well layered or trimmed to fine-tune comfort level

Can I customize or trim these foams to fit my project?

Yes — the blocks are easy to cut with a serrated knife, electric carving knife, or foam saw for a custom fit. Because each piece is a simple rectangular block, you can stack, glue, or carve edges to match complex seat shapes without special tools.

• Trims cleanly with household cutting tools for precise sizing
• Stack multiple blocks to increase thickness or firmness
• Compatible with common upholstery adhesives and fabrics
• Works for DIY pillows, pet beds, boat seating, and bench cushions

What makes this foam a safe and reliable choice indoors?

Foamma foams are CertiPUR-US certified, meaning they are manufactured without certain harmful chemicals and have low volatile organic compound (VOC) emissions. That lowers odours and supports healthier indoor air quality versus non-certified foams.

• Made in the USA under controlled manufacturing standards
• CertiPUR-US certified for low VOCs and restricted chemicals
• Firm density helps maintain cushion structure over time
• Neutral scent that dissipates quickly when first unpacked

How do I care for these foam inserts once installed?

Foam cores themselves should be kept dry and supported by a breathable cushion cover or case. Removing and airing the foam occasionally helps freshness; the outer cover of a finished cushion can typically be spot-cleaned or machine washed if the fabric allows.

• Keep foam dry; avoid prolonged moisture exposure
• Use removable covers for easy washing and protection
• Rotate cushions periodically to encourage even wear
• Spot-clean stains on the cover; air out foam when possible

Who is this for: These 4" x 20" x 20" Foamma blocks are ideal for homeowners refreshing seat cores, upholsterers needing standardized filler for repairs, crafters building custom pillows or pet beds, and small-business furniture refurbishers. If you want a firm, long-lasting core that’s easy to trim and safe for indoor use, this four-pack offers a ready-to-use solution without the wait or expense of custom fabrication.