Firmness
Type
Pocket Spring
Depth (cm)
27
Number of Layers
3
Trial Period (nights)
Warranty (years)
10
Price Range
£829 to £1,599
Best Sleeping Position(s)
Certifications
Assessed from the specification published by MattressNextDay, captured September 2026, and from regular price comparison across our UK retail partners.
Choose the Canterbury 4450 if you want traditional craftsmanship without a four-figure starting price. Harrison Spinks is an NBF-approved manufacturer, and the wool here carries Authentic Traceable British Wool certification, which means you can verify where it came from. The natural fillings, wool, flax and cotton, wick moisture and breathe better than foam, so if you're a hot sleeper this construction works in your favour. The medium firm feel suits most back and combination sleepers, although very lightweight side sleepers may find it slightly too firm. Yes, £829 to £1,599 is a real spend, but 4450 springs plus micro springs and natural fillings justify it. MattressNextDay lists free next day delivery, delivered flat, not boxed.
Key Features & what's inside
- Cover. A breathable Belgian damask fabric cover. It lets air move through the sleep surface, which helps the natural fillings beneath do their temperature work.
- Comfort Fillings. Wool, Ecotex fibres, flax and sustainably sourced cotton. The wool gives a soft cushioned feel, the Ecotex fibres are made from 100% recyclable materials, and the flax and cotton are breathable, absorbent fibres that wick moisture away from you.
- Support System. 4450 pocket springs combined with micro posture springs. Each pocket spring sits in its own fabric pocket and works independently, while the smaller micro springs contour to the exact shape of your body.
Layer details from mattressnextday.co.uk product page, September 2026.
Who's it NOT for?
Skip this one if you want a boxed mattress you can manoeuvre upstairs alone: it arrives flat, all 27cm of it. It's also not for memory foam lovers, as there's no foam here at all. And if a lengthy home trial matters to you, the retailer page we reviewed doesn't mention one.
Harrison Spinks Canterbury 4450 Mattress
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How firm is the Harrison Spinks Canterbury 4450?
It's rated medium firm. That suits most back and combination sleepers, although lightweight side sleepers may find it a little too firm for pressure relief at the shoulder and hip.
Does the Harrison Spinks Canterbury 4450 have a guarantee?
Yes, the product page states a Harrison Spinks 10 year guarantee. No sleep trial is mentioned on the retailer listing we sourced, so check the return policy with your chosen retailer before ordering.
What is the Canterbury 4450 mattress made of?
It uses 4450 pocket springs with micro posture springs for support, topped with wool, flax, sustainably sourced cotton and Ecotex fibres, under a breathable Belgian damask cover. There's no memory foam, which means a more breathable, responsive feel.
Does the Canterbury 4450 come rolled in a box?
No. MattressNextDay states it arrives flat, not rolled and boxed, which is typical of traditionally built sprung mattresses. Make sure your stairs and doorways can accommodate a full-depth 27cm mattress.
What sizes does the Harrison Spinks Canterbury 4450 come in?
Ten sizes: UK Small Single, Long Small Single, Single, Small Double, Double, King and Super King, plus EU Single, Double and King. Prices range from £829 to £1,599 depending on size.
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