Hypnos Organics 4 King Size Mattress
The Hypnos Organics 4 is a firm, double-sided pocket sprung mattress made from Soil Association certified organic materials, hand-crafted in Buckinghamshire by Royal Warrant holders.
- Latex eases hip & shoulder pressure
- Double-sided to even out wear
- Handmade in Buckinghamshire
£4,199
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Hypnos Organics 4 Mattress
More available sizes
Mattress details
Mattress
Hypnos Organics 4 Mattress
Size
Firmness
Firm
Construction
Pocket Spring
Wool
Latex
Depth (cm)
29
Layers
6
Layer Details
Sleep surface
An organic wool and cotton sleep surface that breathes naturally. This helps regulate temperature, so you're less likely to overheat.
Side-stitching
Three rows of genuine hand-sewn side-stitching, which means the edges stay supportive right to the border. You can sleep or sit near the edge without feeling like you'll roll off.
Organic lambswool and peace silk
Layers of pure organic British lambswool and ethically farmed peace silk. These add soft, natural cushioning close to the surface.
Natural moisture-wicking layer
A natural blanket of cotton, hemp and flax that wicks moisture away. Useful if you tend to sleep warm or clammy.
Natural latex
A natural latex layer that relieves pressure across the body. You should feel this as gentle give under hips and shoulders despite the firm feel.
Pocket springs
Hypnos' ReActivePro 7-turn pocket springs respond individually to the shape of your body. This encourages natural spinal alignment for a more comfortable sleep.
Layer details from featherandblack.com product page, September 2026.
Key benefits
- Less disturbance when one of you moves: The ReActivePro 7-turn pocket springs respond individually, and at 75cm each you're far enough apart that an early alarm on one side barely registers on the other.
- Extra length for taller sleepers: At 200cm, the UK king is 10cm longer than the UK double, which means anyone approaching six foot stops finding their feet at the end of the bed.
- Edge support across the full 150cm: Three rows of hand-sewn side-stitching keep the edges firm, so you can use the whole width of the mattress rather than drifting towards the middle.
- Breathable width for two warm sleepers: The organic wool and cotton surface, plus the cotton, hemp and flax layer, wicks moisture away, and the wider footprint means less shared body heat overnight.
- Room to change position: The natural latex eases pressure at hips and shoulders, and the extra 15cm over a UK double gives you space to shift without nudging a partner awake.
This size suits you if...
You share the bed every night and a double has started to feel cramped, especially if one of you gets up hours before the other and you'd like that exit to go unnoticed. It also fits if either of you is approaching six foot, since the 200cm length removes the footboard problem, or if a pet has quietly claimed a share of the bed and 75cm each no longer describes reality.
Consider another size if...
Your bedroom is under our suggested 2.7m x 2.9m minimum, or you sleep alone. We'd recommend the UK double instead, which needs a slightly smaller room at 2.6m x 2.8m and keeps every layer of this mattress intact.
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FAQ's
Is the Hypnos Organics 4 UK king big enough for two people?
Comfortably, for most couples. At 150 x 200cm you get 75cm each, noticeably more personal space than a UK double offers. Because the 7-turn pocket springs respond to each body individually, that extra width translates into less movement transfer, so partners on different schedules disturb each other less.
What room size do I need for a UK king Hypnos Organics 4?
We suggest a minimum of 2.7m x 2.9m, with around 3.2m x 3.2m feeling genuinely comfortable. Measure with wardrobes and drawers in place rather than the empty room, particularly in a new build master bedroom, which can shrink surprisingly once furniture goes in.
Should I choose the UK king or UK super king Hypnos Organics 4?
The UK super king is 30cm wider than the UK king, and both are the same 200cm length, so the choice is purely about width and room size. We suggest at least 3m x 2.9m for the UK super king. If your room clears that easily and you both spread out, size up.
Is the UK king long enough for a tall sleeper?
At 200cm, the UK king is 10cm longer than the UK double, which is usually the difference between feet hanging off the end and lying flat in comfort for anyone around six foot. If length is your main reason for upgrading, the UK king delivers it without demanding a much bigger room.
Is the Hypnos Organics 4 hard to flip in a king size?
It's a double-sided mattress that needs turning to even out wear, and at 150 x 200cm this is realistically a two-person job. Plan to flip it together rather than wrestling it solo. The payoff is longevity: rotating and flipping spreads the wear that single-sided mattresses simply absorb in one spot.