Product knowledge · Home Furniture China editorial · 29 October 2026
The practical answer
A sofa feels the way it does because the whole seating system works together: frame, suspension, cushion core, surface layers, upholstery and proportions. Compare that system on the actual model, in the configuration you intend to buy. Foam density, a spring description or the word premium does not by itself establish whether the seat will feel right for you. Ask how the cushions should be maintained and what can be replaced later. A sofa that suits an upright conversation area may be a different choice from one intended for stretched-out evening relaxation.
Start with the seated activity
Before discussing filling materials, decide how the sofa will be used. A seat for conversation and reading may need a different balance of back support, depth and posture from a lounge used mainly for television. Include the people with the shortest and longest comfortable reach in the comparison. The same deep seat can feel generous to one person and difficult to use without extra support to another.
Try the position you actually expect to use. Sit back, stand up, change position and use the arm as you would at home. A brief press with a hand tells very little about prolonged comfort. If a showroom visit is impossible, request the model’s dimensions and construction information, then compare them with a seat you already know well.
Distinguish the frame from the suspension
The frame gives the sofa its structure. The suspension supports the seating area and interacts with the cushion above it. Manufacturers use different arrangements, including webbing and spring systems; the mere presence of a named material does not reveal how the finished seat behaves. Ask for a description or diagram of the actual model rather than assuming every sofa from the brand uses the same construction.
Modular furniture adds another relationship: how units connect and how the assembled layout is supported. Ask where legs and connectors are located and what assembly is required. If you plan to rearrange the modules, check the approved configurations. A visually attractive arrangement should still follow the maker's intended support and connection system.
Read cushion ingredients without inventing a score
A cushion can combine a structural core with softer surrounding layers. Foam, springs, fibres and feather-containing constructions are used in different combinations. IKEA’s published product descriptions illustrate that individual models can combine pocket springs, high-resilience foam and fibres; that is evidence of those particular product constructions, not a universal recipe for a superior sofa.
Ask what the offered cushion contains and whether the seat and back cushions differ. If density is supplied, clarify which layer it describes and avoid treating it as a direct measure of firmness or a guaranteed lifespan. Product performance depends on more than one number. A helpful supplier can explain the intended feel and maintenance of its complete seat rather than relying on a technical term alone.
| Part | Ask about | Compare in person |
|---|---|---|
| Frame and connectors | Model construction and assembly | Stability and approved arrangement |
| Seat support | Suspension arrangement | Response when sitting and moving |
| Seat cushion | Core and surrounding layers | Support and preferred feel |
| Back cushion | Filling and maintenance | Posture and reachable depth |
Expect different maintenance from different designs
Some cushions are intended to retain a more defined appearance; others are designed for a relaxed look that may require regular dressing or repositioning. Obtain the model-specific instructions before choosing. Ask whether cushions can be turned, swapped or removed, and whether each side uses the same upholstery. An assumption about reversibility can be wrong even when a cushion appears symmetrical.
Consider who will carry out that maintenance. A family may happily reshape a soft lounge cushion but prefer a tidier seat in a formal sitting room. The appropriate choice is the one whose expected appearance and upkeep fit the room’s use. Record the approved method rather than using the same routine for every filled or upholstered component.
Compare dimensions with real body contact
Overall sofa depth does not equal usable seat depth. Back cushions, arm form and upholstery thickness affect the space available for sitting. Likewise, an external height can be misleading if it includes a decorative back above the point that supports the user. Ask the manufacturer how its quoted dimensions are measured.
Use a simple comparison sheet with total footprint, usable seat dimensions where supplied, seat arrangement and cushion information. Place the chosen sofa outline in the room plan and check the surrounding tables. Comfort includes reaching a drink, moving past another person and getting up without an awkward route. These relationships deserve as much attention as the cushion ingredients.
Ask about parts and aftercare
Find out whether replacement seat inserts, covers, connectors or feet can be ordered for the model. Ask which item and material references should be retained and whether a replacement part will need professional fitting. Availability can change, so retain the supplier's current written answer without treating it as an indefinite promise.
If the sofa develops an issue, describe the part and the behaviour rather than diagnosing it from a photograph online. Is the change in a removable cushion, a connection between modules or the underlying frame? Clear pictures and the original order specification help the supplier assess the matter. Understanding the layers before purchase makes that future conversation more precise and also helps you choose a product you can maintain.
A worked planning example
Planning example: a homeowner likes the appearance of a low modular sofa but also needs an upright seat for reading. During comparison, the buyer records the usable seat information, tests the model in a showroom and asks how the cushions should be dressed. The buyer then uses the modular sofa for the lounge area and a different chair for the reading corner. This hypothetical scheme solves two activities directly instead of expecting one filling material to satisfy every posture. No product testing or measured lifespan is claimed.
Questions readers ask
Is firmer foam always more durable?
Firmness alone is not a complete durability measure. Ask for the actual cushion construction and the maker’s performance information. Compare the feel on the complete sofa, not an isolated foam description.
Do springs automatically make a sofa better?
A spring description identifies one part of a system. Frame, suspension, cushion layers and proportions all matter. Compare the actual product and obtain its intended-use and maintenance guidance.
Can I replace only the cushion filling later?
That depends on the model. Ask whether inserts are accessible and available, what reference is needed and whether replacement affects the product’s fit or support. Keep the supplier’s written answer with the order.
Sources and further reading
The sources support the material and product distinctions discussed above. Room arrangements and worked examples are our editorial planning guidance.