Harrison Spinks Platinum 12500 Pocket Mattress (Soft to Medium Feel)
The Harrison Spinks Platinum 12500 is a soft to medium pocket spring mattress, handcrafted in the UK from natural fibres including British wool, cotton, hemp and flax.
- Pressure relief suited to side sleepers
- Wool regulates temperature naturally
- Support builds as you sink in
£1,199
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The Harrison Spinks Platinum 12500 is 29cm deep and contains 12,500 springs in total, which means the surface can respond to your body in small, precise ways rather than as one broad sheet of support. It's foam-free, so it suits sleepers who want a breathable, natural build. It's a considered purchase rather than an impulse one, but the spring engineering and natural fillings go some way to justifying it. If you prefer a gently cushioned feel over a firm one, it's a strong candidate.
Mattress specifications
Firmness
Medium Soft
Type
Pocket Spring
Depth (cm)
29
Number of Layers
5
Trial Period (nights)
100
Warranty (years)
5
Price Range
£1,199 to £2,299
Best Sleeping Position(s)
Side Sleeping
Certifications
BS 7177
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
Why should you choose this mattress?
The main draw is the support system. Beneath the comfort layers sit 10,500 mini springs and 1,000 Posturfil springs, with a base of 1,000 Cortec Quad Revolution springs grouped in fours, each with a mini spring inside. In practice that means pressure relief that adjusts to your weight and movement, which side sleepers in particular tend to appreciate. The fillings are natural: British wool for temperature regulation, plus cotton, hemp and flax for durability, and a layer of recycled Ecotex fibres. It conforms to BS7177: 2008 and Harrison Spinks is a National Bed Federation Approved Brand. Buying through Mattress Online gets you a 100-night trial, though that's the retailer's offer rather than the brand's.
Key features & layer details
Comfort Layer
Plush British wool sits at the top, which means natural temperature regulation. Wool wicks moisture, so you stay cosy in winter and cooler in summer.
Comfort Blend
Cotton and wool fibres are blended with hemp and flax. These tougher plant fibres help the comfort layers keep their shape over time.
Sustainable Layer
A layer of Ecotex fibres made from recycled materials. It's there for strength and durability rather than softness.
Support System
10,500 mini springs contour closely to your body, backed by 1,000 Posturfil springs that flex with your movements and weight distribution. This is where the personalised, cradling feel comes from.
Spring System
At the base, 1,000 Cortec Quad Revolution springs sit in individual pockets, secured in groups of four, with a mini spring inside each one. That layered spring-within-a-spring design gives progressive support as you sink in.
Layer details from mattressonline.co.uk product page, September 2026.
Best suited for?
Side sleepers
The 10,500 mini springs and 1,000 Posturfil springs adjust to your weight and movement, giving shoulders and hips the cushioned, contouring feel side sleepers tend to like.
Warm sleepers
A top layer of British wool wicks moisture and regulates temperature, and the foam-free build keeps things breathable, so you should stay cooler in summer.
Eco-conscious buyers
Natural fillings including British wool, cotton, hemp and flax sit alongside a layer of recycled Ecotex fibres, all in a foam-free construction.
Combination sleepers
Posturfil springs flex with your movements and weight distribution, so the surface keeps responding as you shift between positions during the night.
Couples
Individually pocketed Cortec Quad Revolution springs, grouped in fours with a mini spring inside each, give progressive support so each partner gets a surface that responds on their own side.
This is a soft to medium mattress, so it's not the right pick if you need a firm surface. Heavier sleepers, and back or stomach sleepers who prefer a flatter, more resistant feel, may find it a little too yielding. The starting price also puts it out of reach for tighter budgets.
Save on an earlier or ex-display model
Some retailers still sell the earlier version of this mattress, or ex-display and returned stock at a lower price. These are the sizes where it costs less than the current model's best price.
Harrison Spinks Platinum 12500 Pocket Mattress (Soft to Medium Feel)
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FAQ's
How many springs does the Harrison Spinks Platinum 12500 have?
12,500 in total. That breaks down as 10,500 mini springs and 1,000 Posturfil springs in the support system, plus 1,000 Cortec Quad Revolution springs at the base, each with a mini spring inside it.
Is the Harrison Spinks Platinum 12500 soft or firm?
It's described as soft to medium. That gently cushioned feel suits most side sleepers and lighter builds, although anyone who prefers a firm mattress should look elsewhere.
Does the Harrison Spinks Platinum 12500 come with a trial?
Mattress Online lists a 100-night trial with this mattress. That's the retailer's own offer rather than a Harrison Spinks policy, so check the terms wherever you buy.
How deep is the Harrison Spinks Platinum 12500?
It's 29cm deep. That's on the deeper side, so check your fitted sheets will stretch to it before it arrives.
What guarantee does the Harrison Spinks Platinum 12500 have?
The Mattress Online listing states a 5 year guarantee. Confirm the guarantee terms with your retailer at the point of purchase, as cover can differ between sellers.
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