The short answer
Artificial grass yarn comes in three main plastics, each with a job to do. Polyethylene (PE) is the soft, natural-feeling fibre used for the long green blades on most UK lawns. Polypropylene (PP) is stiffer and cheaper, used mainly for the short curly thatch that supports the pile and hides the backing. Nylon (polyamide) is the toughest and most heat-resistant, but stiffest underfoot, so it is reserved for sports surfaces, putting greens and very high-traffic areas. On top of the plastic, the blade shape matters — cross-sections such as C-shape, V-shape, diamond or spine change how upright and resilient the grass stays. A good landscaping grass blends fibre types and uses a shaped blade so the pile looks natural and springs back rather than lying flat.
Yarn is the part of artificial grass you see and feel, so the fibres and their shapes drive how natural a lawn looks. Knowing the three plastics and the common blade shapes helps you read a spec sheet and judge quality.
Yarn types at a glance
- Soft green bladesPolyethylene (PE)
- Curly thatchPolypropylene (PP)
- Sports / high trafficNylon (polyamide)
- Common blade shapesC, V, diamond, spine
- What shape changesHow upright the pile stays
The three fibre plastics
Almost all artificial grass yarn is one of three plastics, often blended within a single product:
- Polyethylene (PE): the workhorse of landscaping grass. It is soft, has a natural matt sheen and recovers reasonably from footfall, which makes it the go-to fibre for the long green blades on domestic lawns. It strikes a good balance between looks, feel and durability.
- Polypropylene (PP): a stiffer, more economical fibre. It is rarely used for the main blades of a quality lawn because it can look shiny and flatten, but it is ideal for the short, curly, brown-and-tan thatch at the base that mimics real lawn and helps the long blades stand up.
- Nylon (polyamide): the strongest and most heat-tolerant fibre, but the stiffest underfoot. Its toughness suits putting greens, sports pitches and intensely used commercial areas rather than family lawns where softness matters.
Why blade shape matters as much as plastic
The plastic is only half the story. Manufacturers extrude each blade with a particular cross-section, and that shape strongly affects how the grass performs:
- Flat blade: the simplest shape. Soft but more prone to lying flat and looking shiny.
- C-shape: curved like a letter C, which adds stiffness and helps the blade stand upright and resist matting.
- V-shape: a folded profile that improves resilience and gives a more textured look.
- Diamond / oval: shapes that scatter light to reduce shine and look more natural.
- Spine or rib: a raised central rib down the blade for extra stiffness, so the pile springs back strongly after being walked on.
A shaped or spined blade in soft polyethylene is a common sign of a better grass: it keeps the natural feel while resisting the flattening that makes cheap grass look tired.
| Fibre / shape | Character | Typical use |
|---|---|---|
| Polyethylene | Soft, natural, resilient | Main green blades, lawns |
| Polypropylene | Stiff, economical | Thatch layer, short surfaces |
| Nylon | Very tough, heat-resistant, stiff | Sport, putting greens |
| C / V / spine shapes | Added stiffness, less shine | Quality landscaping grass |
Indicative guidance. Most lawns blend fibres and shapes.
Choosing the right yarn for your lawn
For a normal garden lawn, look for a grass whose main blades are polyethylene, ideally with a shaped or spined profile, plus a polypropylene thatch for support and realism. This combination gives a soft, natural feel with good upright recovery.
Choose differently when the use is unusual:
- Heavy traffic or play: favour a denser grass with robust, shaped blades; some products use nylon elements for extra wear resistance.
- Putting green or sport: a short, dense nylon or hard-wearing surface is appropriate, accepting a firmer feel.
- Pets: durability and easy cleaning matter, so a dense polyethylene pile with a good backing tends to suit.
As always, the fibre type is one factor among several — density, pile height and backing all play a part. Feeling a sample is the surest way to judge whether a yarn is as soft and resilient as the spec suggests.
How yarn type affects feel, heat and lifespan
The fibre choice does more than set how soft a lawn feels — it influences three practical things worth weighing up before you buy.
Feel underfoot. Polyethylene is the most pleasant to sit, kneel or lie on, which matters for family gardens where children play on the grass. Polypropylene and nylon are firmer; nylon in particular can feel quite stiff, which is fine on a putting green you stand on but less inviting on a lawn you want to relax on. If softness is a priority, the main blades should be polyethylene.
Heat in the sun. All synthetic grass warms up in direct sun more than real grass does, and fibre type plays a part. Nylon tends to retain heat and can feel hotter underfoot, which is another reason it is reserved for sports use rather than gardens. Polyethylene grasses generally feel cooler, though colour, infill and sun exposure matter too. On the hottest days a quick rinse with the hose cools any artificial lawn down.
Lifespan and recovery. Durability comes from the combination of fibre and shape. Nylon is the toughest fibre but is overkill for most gardens; a good-quality polyethylene blade with a reinforcing spine resists matting and recovers well from footfall, giving a long life without the stiffness of nylon. The thatch, usually polypropylene, supports the longer blades and helps them stand back up.
- For softness and looks: polyethylene blades, shaped profile, polypropylene thatch.
- For heavy traffic: dense polyethylene with robust, spined blades.
- For sport or putting greens: short, dense nylon or hard-wearing surface, accepting a firmer feel and more heat retention.
In short, no single fibre is best for everything — the right yarn depends on whether you are prioritising comfort, durability for sport, or a natural garden look, and most quality lawns combine fibres to balance these.
Frequently asked questions
Which artificial grass yarn is the softest?
Polyethylene is the softest of the common fibres and is used for the long green blades on most domestic lawns. Polypropylene is stiffer and mainly used for the thatch, while nylon is the toughest but the firmest underfoot. For a soft, lawn-like feel, look for a grass with polyethylene blades.
Is nylon artificial grass better than polyethylene?
Nylon is tougher and more heat-resistant, which suits sports surfaces and very high-traffic areas, but it is stiffer and less pleasant underfoot for a garden. Polyethylene gives a softer, more natural lawn feel. Better is not absolute here — it depends on whether you prioritise durability for sport or softness for a domestic lawn.
What is the curly brown grass in artificial turf?
That is the thatch layer, usually made from stiff polypropylene fibres in brown and tan tones. It sits at the base of the pile to mimic the dead grass found in a real lawn, hide the backing, and help the longer green blades stand upright. A good thatch is one of the things that makes artificial grass look natural.
Sources & further reading
Figures on this page are typical UK ranges drawn from published cost guides and are intended as guidance, not a quotation.