Choosing the correct foam grade is essential for achieving the right balance of comfort, support, durability and safety. Whether you are working on residential seating, commercial upholstery, marine cushions, packaging, bedding or specialised manufacturing, selecting the appropriate foam will determine how well your finished product performs over time.
At Enviro-Foam, we manufacture and supply custom-cut foam in a wide range of grades to suit virtually any application across Queensland and Australia.
1. What Does “Foam Grade” Mean?
When selecting foam, two technical factors matter most: density and firmness.
Density (kg/m³)
Density refers to the mass per cubic metre of foam.
- Higher density = greater durability and longevity
- Lower density = lighter weight and typically more economical
- Density does not directly determine firmness
Density affects lifespan and structural integrity.
Firmness / ILD (Indentation Load Deflection)
Firmness, often measured in Newtons (N) or ILD, refers to how soft or firm the foam feels.
- Higher ILD = firmer foam
- Lower ILD = softer feel
Firmness determines comfort and level of support.
The ideal foam grade combines the right density for durability with the right firmness for the intended use.
2. Matching Foam Grades to Applications
Different projects require different foam specifications. Below is a general guide to help you select the right foam for common uses.
Upholstery Foam
Seat Cushions (Residential Use)
- Medium to high density: 30–36 kg/m³
- Medium-firm ILD: 120–160N
Back Cushions
- Lower density: 20–28 kg/m³
- Soft ILD: 60–100N
Commercial or Heavy-Use Furniture
- High density: 36–40+ kg/m³
- Medium-firm to firm ILD
For sofas, bench seating, banquettes and replacement lounge cushions, selecting the correct grade ensures consistent support and prevents premature sagging.
Acoustic & Soundproofing Foam
In acoustic applications, density is less critical than cell structure and surface profile.
Look for open-cell polyurethane foam with specialised acoustic profiles such as eggcrate, wedge or pyramid designs. These are ideal for studios, offices, theatres and machinery noise control.
Packaging Foam
Different materials suit different packaging needs.
For fragile items, use soft, low-ILD polyurethane foam.
For sensitive electronics, use anti-static foam.
For tool inserts or precision cut-outs, choose cross-linked polyethylene (XLPE) or EVA foam for clean edges and durability.
Custom CNC cutting ensures a secure fit and professional finish.
Outdoor & Marine Foam
For marine and outdoor environments, moisture resistance is critical.
Choose reticulated (quick-dry) open-cell foam, which:
- Allows water to drain freely
- Resists mould and mildew
- Performs well in humid conditions
- Is typically mid-to-high density for durability
This makes it ideal for boats, caravans, poolside seating and outdoor lounges.
Mattresses & Bedding Foam
Mattress construction usually combines multiple foam grades.
Comfort layers use low to medium density with a softer ILD.
Support cores use high density, firmer foam for structure and longevity.
Specialty options include memory foam for pressure relief and high-resilience (HR) foam for durability and responsiveness.
Custom mattress foam can be tailored for residential, caravan, marine and specialty bedding projects.
3. Environmental & Safety Considerations
Depending on your industry or location, you may require:
- Fire-retardant foam grades compliant with standards such as AS/NZS 1530.3
- Low-VOC or non-toxic formulations
- Anti-microbial or anti-allergen treatments
- Waterproof or hydrophobic finishes
Public spaces, schools, hospitals and commercial premises often require certified fire-safe foam. Always confirm compliance requirements before manufacturing.
4. Consider Usage Frequency
How often the foam will be used impacts the grade required.
Light Use
Decorative cushions or occasional chairs may only require lower density foam.
Medium Use
Household sofas and everyday seating benefit from medium density and medium ILD grades.
Heavy Use
Commercial seating, gym mats and high-traffic environments require high density and firmer grades for long-term performance.
5. Thickness, Shape & Structural Design
Foam thickness significantly influences performance.
Thicker foam generally feels softer at the same density.
Thin foam must be firmer to provide adequate support.
Complex shapes or CNC-cut designs may require high-resilience or closed-cell foams for structural integrity and edge stability.
Selecting the correct combination of thickness and grade is essential for long-term durability.
6. Specialty Foam Options
Certain projects require specialised materials.
Memory foam offers pressure relief and contouring.
High-resilience (HR) foam provides premium performance and long lifespan.
Closed-cell foam is waterproof, buoyant and impact-resistant.
Reticulated foam is ideal for marine and airflow applications.
EVA and PE foams are commonly used for gym flooring, packaging and industrial inserts.
Choosing the right specialty foam ensures performance, safety and longevity.
7. Test Before You Commit
Whenever possible:
- Request samples
- Apply real-world pressure by sitting or compressing
- Check recovery speed and comfort
Testing prevents costly mistakes and ensures you select the correct foam grade for your project.
8. Work with a Foam Specialist
Choosing foam is not just about numbers. It is about understanding how the material will perform in real-world conditions.
Enviro-Foam provides:
- Custom-cut foam to any size or shape
- Expert guidance on density, firmness and material selection
- Foam solutions for upholstery, bedding, acoustic, marine, packaging and industrial applications
- Environmentally conscious foam options
Whether you need a single cushion insert or large-scale manufacturing supply, our Brisbane-based team can help you select the right foam grade with confidence.
Contact Enviro-Foam today to discuss your project specifications and receive expert advice on the best foam solution for your application.