Harrison Spinks Platinum 12500 Pocket Mattress (Firmer Feel)
Mattress
Harrison Spinks Platinum 12500 Pocket Mattress (Firmer Feel)
Size
Firmness
Firm
Construction
Depth (cm)
29
Layers
6
Layer Details
- Comfort fillings. Layers of plush British wool sit at the top, which means natural temperature regulation. You should feel cosy in winter and cooler in summer.
- Comfort fillings blend. Cotton and wool fibres are blended with hemp and flax. These tougher plant fibres help the comfort layers keep their shape over time.
- Ecotex layer. A layer of Ecotex fibres made from recycled materials. It adds strength and durability rather than a feel you'd notice directly.
- Mini Pocket Springs. Layers of 10,500 mini springs contour to your body. Because each spring moves independently, the surface adapts to your shape for a more personalised feel.
- Posturfil springs. An additional 1,000 Posturfil springs respond to your movements and how your weight is distributed. In practice, this means flexible support that adjusts as you change position.
- Cortec Quad Revolution springs. The base layer of 1,000 Cortec Quad Revolution springs adapts to your body for deeper support. Each one has a mini spring inside it, so you get two stages of response from a single spring.
Layer details from mattressonline.co.uk product page, September 2026.
- A premium build in a compact footprint: At 90cm wide it slots into box rooms, loft conversions and spare rooms where anything wider would crowd the walkway.
- Natural fillings for one sleeper: British wool regulates temperature across the whole 90cm surface, which means a solo sleeper is less likely to overheat in summer.
- Built for years, sized for a teenager: Hemp and flax fibres help the comfort layers hold their shape, useful when the mattress needs to last through the teenage years.
- Springs that respond to lighter bodies: The three spring layers move independently, so a lighter single sleeper still gets contouring rather than lying on top of an unyielding surface.
- Cheap, easy bedding: Standard single sheets and a 135 x 200cm single duvet fit, and they're the most widely stocked bedding of any UK size.
This size suits you if...
You're a single adult, teenager or older child who wants natural materials rather than foam, and you have a room of at least 2.1m x 2.8m. It also suits a guest room or a spare room doubling as an office, where a long-lasting mattress in the smallest standard footprint makes sense, or a student moving into a first flat where the frame is provided but the mattress isn't.
Consider another size if...
You're an adult who spreads out in the night, or the bed will occasionally sleep two. We'd recommend the UK small double instead: it's 30cm wider than the UK single, the same length, and we suggest at least 2.4m x 2.8m of room for it.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
What size room do I need for a UK single mattress?
We suggest at least 2.1m x 2.8m of floor space for a UK single, which is Mattress Unboxed's own guidance rather than the manufacturer's. That leaves room to walk round and open drawers. In a child's bedroom competing with a wardrobe, desk and toy storage, the 90cm width of the UK single keeps the most floor free of any standard adult size.
Is the Platinum 12500 in a UK single suitable for a bunk or mid sleeper?
Check your frame's maximum mattress depth first. The Platinum 12500 is 29cm deep, which is more than many bunk and mid-sleeper frames allow, since a deep mattress can bring a child above the safety rail. The UK single footprint of 90 x 190cm matches most bunk frames, but the depth is the sticking point here.
Is the Harrison Spinks Platinum 12500 single a good choice for a child's room?
The size is right: a UK single is the standard children's bed size, and the wool, hemp and flax fillings are built to keep their shape for years. That said, this is a serious spend for a child's mattress, and despite the name it's listed as a soft to medium feel, so check that suits how your child sleeps.
Can two UK singles work in a guest room instead of a double?
Yes, and it's a flexible arrangement: two UK singles at 90cm wide each suit guests who'd rather not share, and can be pushed together when a couple stays. You'll need space for both beds plus a walkway between them, so measure carefully. Compare the retailers listed on this page for the current UK single price.
What bedding do I need for the Platinum 12500 in a single?
Standard UK single bedding fits the 90 x 190cm footprint, with a 135 x 200cm single duvet. One thing to watch: at 29cm this is a deep mattress, so choose fitted sheets with a deep box, ideally listed for mattresses of 30cm or more, otherwise the corners will keep pinging off.