Mattress Fillings: Soft and Firm Materials and How to Choose

Buyers choose a mattress by feel: soft or firm, "hugging" or "supportive". Behind these sensations lies not only the spring unit but also the fillings — layers that distribute load and are responsible for comfort, ventilation and durability. For a manufacturer, choosing the right fillings is a balance between consumer properties and cost. Let's look at which materials are used, how soft fillings differ from firm ones and how to build a successful construction from them.

Why a mattress needs fillings: the role of each layer

Every layer in a mattress has its own job:

• the insulator layer separates the spring unit from soft materials, stops springs from pushing through the filling and protects it from wear;
• the support (firm) layer sets the resilience and spinal support;
• the comfort (soft) layer determines the first feel on contact and adapts to the body at pressure points;
• the quilted top joins the soft layer with the cover and shapes the look.

A mistake in any layer will be noticed by the buyer: an insulator that is too thin and springs can be felt within a year; a poor comfort layer and the mattress feels "like a board".

Soft fillings

Soft materials create the comfort and "character" of a mattress. The main options:

• PU foam (polyurethane foam) in various grades and densities — a versatile, affordable material for comfort layers and springless models.
• Memory foam — slowly conforms to the body and reduces pressure on shoulders and hips; valued in the mid-range and premium segments.
• Latex — natural, synthetic or blended; resilient, durable and well ventilated. Zoned cores with different firmness for shoulders, lower back and legs are also available.
• Polyester wadding and hollow fibre — lofty fibrous materials for quilting and a soft top layer.

You can choose materials in the soft mattress fillings section. How the soft layer works in a quilted top is covered in our article on thermal and mattress quilting.

Firm fillings

Firm materials are responsible for support and structural stability:

• Coconut coir — coconut husk fibre bonded with latex or thermal fibre. Provides high firmness and good ventilation; popular in orthopaedic and children's models.
• Strutto fibre and thermally bonded pads — vertically laid polyester fibres; resilient, lightweight and hypoallergenic, a medium-firm alternative to coir.
• Thermal felt and technical pads — used as an insulator above the spring unit: they spread the load evenly and protect the soft layers.

Browse the range in the firm fillings section. Non-woven materials are also used for insulation and backing.

How to combine layers: construction examples

Spring mattress

The basic build-up: spring unit — insulator (thermal felt) — firm or medium layer — comfort layer — quilted cover. Pocket spring units are usually paired with softer comfort layers, while Bonnell units need a denser insulator. Learn more about choosing the base in our article Bonnell or pocket spring unit and in the pocket spring units section.

Springless mattress

The base is a PU foam or latex core supplemented by layers of different firmness. A popular scheme is "winter/summer" or "dual firmness": coir on one side for firm support, latex or soft foam on the other.

Double-sided models

Different layers on each side let you sell one mattress as a "two in one" — a strong argument in the product listing and in the showroom.

Layers are usually bonded with adhesive; choose a dedicated mattress adhesive compatible with foam, latex and fibrous materials.

Durability and hygiene of fillings

When choosing fillings, think not only about the first impression but also about how the mattress will perform after several years of use:

• Compression set. Low-density foam sags over time, so for top layers it is better to choose materials with a density margin.
• Ventilation. Coir, perforated latex and fibrous materials let air through and reduce moisture build-up inside the mattress.
• Hypoallergenic properties. Synthetic fibres do not attract dust mites and are well suited to children's models.
• Documentation. Ask the supplier for composition and density data — you will need it for labelling and for answering buyers' questions.

Practical tips for selection and purchasing

1. Start from the target segment. First define the feel and shelf price, then select materials — not the other way round.
2. Compare density, not just thickness. Two layers of the same thickness can behave completely differently.
3. Request samples and assemble a test build-up: it is easier to judge how the layers work together.
4. Check odour and packaging. Quality materials should have no strong smell after airing; packaging should protect against moisture and deformation.
5. Consider cutting. Confirm standard sheet and roll sizes to reduce waste.
6. Plan deliveries in advance. Bulky materials need warehouse space — agree the shipping schedule with your manager.

Well-chosen fillings turn a set of materials into a mattress with a clear character — soft, medium or firm — that meets buyer expectations and keeps its properties over time.

Need filling samples or help designing a construction? Request samples and a price list via our contacts page — a manager will suggest options for your model and confirm delivery terms across Kazakhstan.