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BRAIN SLEEP’s warmest comforter to date
An exceptionally
warm comforter
that goes
beyond down
Featuring an industry-first patented material "Carbon Nano Down"
An ideal in-bed temperature
that feels warm and comfortable
even in extreme cold environments of
31.3°C
is maintained
Simply by using COMFORTER PERFECT WARM EX
even in environments
as cold as −14°C
Inside the comforter
the temperature is kept comfortable.
Compared with premium down comforters, it delivers 196% higher warmth performance while also supporting an ideal in-bed environment.
A major update to the functions of
the previous PERFECT WARM EX
with an even softer, lighter feel
that goes beyond down
Infused with BRAIN SLEEP’s expertise
and proprietary patented technologies
A one-of-a-kind ultimate comforter is introduced
The secret lies in revolutionary
carbon
technology
developedBRAIN SLEEP
CARBON TECHNOLOGY
The filling uses a proprietary, patented material, Carbon Nano Down.
A special carbon treatment is applied to the fibers, enabling warmth, comfort, and cleanliness in a single advanced filling.
Its large, interlocking particle structure traps warm air effectively,
maximizing heat retention.
A next-generation filling developed in Japan.
*Based on bedding filling materials available in Japan as of September 2025.
Heat retention
Moisture absorption and heat generation
Moisture absorption and release
Low lint shedding
Far-infrared radiant heat
Antibacterial
Mite-resistant
Deodorizing
Washable
Resilient recovery
*Based on bedding filling materials available in Japan as of September 2025.
A proprietary, next-generation filling
A multifunctional hybrid
particle filling
Carbon Nano Down
Patent No. 7734358
Using advanced technology,
it delivers exceptional heat retention,
while also supporting comfort and cleanliness.
A carbon treatment is applied to the reverse side of the ultra-lightweight fabric.
This treatment prevents heat from escaping the comforter,
shielding the inside from cold external air.
Thermal insulation
A proprietary, next-generation filling
A multifunctional hybrid
particle filling
Carbon Nano Down
Patent No. 7734358
Using advanced technology,
it delivers exceptional heat retention,
while also supporting comfort and cleanliness.
More than warmth,
comfort and cleanliness
that go beyond down
| Down | PERFECT WARM EX | |
| Heat retention | ○ | ◎ |
| Heat generation | × | ◎ |
| Radiant heat | × | ◎ |
| Resistance to dampness | × | ◎ |
| Cleanliness | × | ◎ |
| Odor resistance | × | ◎ |
| Fit | △ | ◎ |
| Washability | × | ◎ |
| Resilience | ○ | ◎ |
| Dust release | High | Low |
| Ease of storage | △ | ◎ |
| Maintenance | Down | Carbon Nano Down |
TECHNOLOGY
01PERFECT WARM EX
Warmth that goes far beyond down
The warmest comforter in BRAIN SLEEP history
Compared with premium goose down comforters containing 93% down, it achieves approximately 196% higher heat retention.
Using PERFECT WARM EX raises the in-bed temperature by up to 6.6°C
Using PERFECT WARM EX raises the in-bed temperature by up to 6.6°C
Under assumed winter conditions, using PERFECT WARM EX raises the in-bed temperature by 6.6°C within 20 minutes,
achieving an ideal in-bed temperature of approximately 33.0°C
Warmth performance that goes far beyond down
Warmth performance that goes far beyond down
Compared with premium goose down comforters among down products,
it achieves approximately 196% higher warmth performance.
Extra Carbon Nano Down at the shoulder and foot areas prone to cold
Extra Carbon Nano Down at the shoulder and foot areas prone to cold
The shoulder and foot areas, where heat is most likely to escape, are filled with additional Carbon Nano Down to help block out cold external air during sleep.
POWER UP
Proprietary carbon technology
powered by advanced innovation
POWER UP
Proprietary carbon technology
powered by advanced innovation
Through a special carbon treatment applied to both the outer fabric and the filling, it delivers ultimate warmth.
Ultimate warmth that goes beyond down
A patented particle filling
Carbon Nano Down
Ultimate warmth that goes beyond down
A patented particle filling
Carbon Nano Down
Carbon is processed at an ultra-fine, nano-scale level and specially integrated into fibers.
These fibers are then formed into particles, creating Carbon Nano Down.
A special structure that traps warmth
A special structure that traps warmth
Carbon Nano Down features large, interlocking particles.
This structure helps retain warm air effectively, delivering exceptional warmth.
Thermal insulation technology that blocks cold air
Thermal insulation technology that blocks cold air
A carbon treatment is applied to the reverse side of the ultra-lightweight fabric.
This thermal insulation technology helps prevent internal warmth from escaping
while shutting out cold air from outside.
02PERFECT COMFORT
An ultimate drape that goes beyond down, delivering light, effortless comfort.
The proprietary brushed fabric on the skin side combines exceptional softness, breathability, and moisture-absorbing heat generation, delivering comforting warmth from the very first moment you slip inside.
POWER UP
Smooth against the skin,
comforting warmth from the moment you slip in.
POWER UP
Smooth against the skin,
comforting warmth from the moment you slip in.
Crafted with a special fiber structure refined to closely resemble cashmere, the fabric achieves a softness and smoothness reminiscent of true cashmere.
POWER UP
Recreating the fiber structure of cashmere and wool
Warm, without feeling clammy
POWER UP
Recreating the fiber structure of cashmere and wool
Warm, without feeling clammy
Cashmere and wool feature a unique fiber structure with scale-like layers that open and close to help regulate moisture.
This structure was recreated from the ground up. As a result, a sleep environment is created that remains warm while maintaining high moisture absorption and release, reducing clamminess.
Moisture is further converted into heat, enhancing heat generation performance.
A one-piece comforter design
that stays in place throughout the night
A one-piece comforter design
that stays in place throughout the night
Shifting that can occur when layering a comforter and blanket is eliminated.
The integrated design allows for use as is, without a cover.
A body-contouring quilt
for a fit that goes beyond down
A body-contouring quilt
for a fit that goes beyond down
A 3D twin quilt construction is used to maximize the performance of Carbon Nano Down.
The double-layer quilting prevents fill from shifting and reduces heat loss through the seams.
The result is a close, body-hugging fit.
Warm, without feeling clammy
for comfortable sleep
Warm, without feeling clammy
for comfortable sleep
Compared with down comforters, breathability is significantly improved.
Moisture is absorbed and released across the entire comforter, helping maintain a dry, comfortable sleep environment.
03PERFECT CLEAN
Perfect cleanliness
A winter comforter that can be washed
in a household washing machine
The entire comforter can be washed, with a clean finish.
Suitable for washing in a household washing machine.
[Recommended washing machine capacity]
• Single / Semi-double size: washing machines with a capacity of 9 kg or more
• Double / Queen size: washing machines with a capacity of 11 kg or more
※Requirements may vary depending on the washing machine model and design.
※Always refer to the manufacturer’s instruction manual.
※Please place the comforter in a laundry net designed for comforters before washing.
※If washing in a household machine is not possible, use a large-capacity coin-operated laundry machine
or a professional comforter cleaning service.
Carbon Nano Down delivers ultimate cleanliness
Carbon Nano Down delivers ultimate cleanliness
Carbon Nano Down used in the filling offers powerful antibacterial and deodorizing properties, suppressing the growth of bacteria, neutralizing unpleasant perspiration odors,
and helping prevent the proliferation of dust mites.
Fiber shedding is limited to just 2% compared to down comforters
Fiber shedding is limited to just 2% compared to down comforters
With minimal fiber release, it can be used comfortably and with confidence every day
Compact storage that takes up minimal space when not in use
Compact storage that takes up minimal space when not in use
Proper storage is an essential part of bedding care.
Stored in the included dedicated bag, the comforter remains compact
and takes up minimal space.
Compression storage is also possible.
Compression storage is also possible.
Unlike traditional down comforters, this comforter can be stored in compression bags, making space-saving storage even easier.
Down comforters are typically not suitable for compression, as feathers may damage the outer fabric and leak out.
SPEC
Size
Single: W150 cm × L210 cm (approx. 2,890 g)
Semi-Double: W170 cm × L210 cm (approx. 3,230 g)
Double: W190 cm × L210 cm (approx. 3,570 g)
Queen: W210 cm × L210 cm (approx. 3,940 g)
Color
Stone Gray
Material
・Outer fabric:
Front: 100% polyester
Back (pile): 100% polyester
Base fabric: 55% polyester, 45% rayon
・Insulation:
85% polyester, 15% acrylic
FAQFrequently asked questions
Find a Store
Yes. It can be washed at home.
Please place the comforter in a laundry net and wash it separately.
Avoid using bleach, including chlorine-based or oxygen-based bleach.
Is it washable?
Yes, it can be washed at home.
Please place the product in a laundry net and wash it separately. (Using a BRAIN SLEEP laundry net designed for comforters.)
As a guideline for washing machine capacity: ingle / Semi-double sizes: washing machines with a capacity of 9 kg or more
Double / Queen sizes: washing machines with a capacity of 11 kg or more
Depending on the shape or model of the washing machine, the product may not fit.
In such cases, hand washing or using a large-capacity coin laundry or a professional bedding cleaning service is recommended.
Avoid forcing the product into the washing machine, as this may cause damage to the machine.
Please check your washing machine’s instruction manual before washing.
Can I use bleach?
To prevent discoloration or fading, please avoid using bleach
(both chlorine-based and oxygen-based).
Can it be tumble-dried?
Tumble drying may cause shrinkage or damage to the product, so please avoid using a tumble dryer.
Can I use a futon dryer?
Yes, a futon dryer can be used.
However, please avoid using a it directly on top of a BRAIN SLEEP mattress or near a BRAIN SLEEP pillow, as heat may alter the shape of the product.
Please tell me how to dry the comforter.
Choose a day with low humidity and good ventilation for washing.
Wash early in the day and hang to dry, alternating both sides to ensure even drying.
When drying, gently pat the product by hand to loosen the filling and restore its fluffiness.
Is there a specialized comforter cover?
This product is designed to be used as is, without a comforter cover.
If you prefer to use a cover, standard-size comforter covers available on the market can be used for all sizes.
Can I use compression storage bags?
Yes, compression storage bags can be used
Please ensure the product is thoroughly washed and completely dried before placing it in a compression storage bag.
When using the product again, remove it from the bag and spread it out to allow air to enter the comforter before use.
What color options are available?
The product is available in one color only: Stone gray
How thick is the comforter?
The comforter has an approximate thickness of 10 cm, offering a fluffy, voluminous feel.
Does the comforter have a front and back side?
Please use the blanket side directly against the skin.
Does static electricity occur?
The material is treated with an anti-static finish.
However, depending on environmental conditions such as low humidity, static electricity may still occur.
If this happens, we recommend adjusting the bedroom humidity using an air conditioner or humidifier, washing the product once, or lightly misting it with water.
Does the product use animal fibers?
No animal fibers are used.
This is an animal-free comforter.
As a result, it does not have animal-related odors. However, depending on humidity and storage conditions, the material itself may develop an odor.
In such cases, we recommend deodorizing and air-drying the product or washing it once.
BRAIN SLEEP COMFORTER comparison chart
No down comforter.
No blanket.
For those seeking
the ultimate level of warmth.
BRAIN SLEEP
MATTRESS PROTECTOR
PERFECT WARM EX
A fitted mattress protector designed for use with mattresses.
BRAIN SLEEP
MATTRESS PROTECTOR
PERFECT WARM EX
A fitted mattress protector designed for use with mattresses.
When used together, it increases heat retention around the back by 112%, while effectively blocking cold air rising from below.
Cold air in winter tends to accumulate near floors and ground surfaces,
and that chill can travel upward through the mattress.
This mattress protector helps shield the body from that cold,
supporting a warmer, more comfortable sleep environment.
Just place it over an existing mattress or mattress pad to create an exceptionally warm, non-clammy sleep environment.
The protector uses Carbon Heat EX for the insulation and the same fabric as Blanket EX.
Compatible mattress height:
Designed for mattresses approximately 20–30 cm thick.
It can also be used with thinner mattresses; however, excess fabric on the underside may occur, so please tuck it in securely during use.
More effective when used together with the comforter and mattress protector
Using the comforter and mattress protector together, above and below, enhances overall warmth.
Size
・Single: W100 cm × L205 cm (approx. 1,140 g)
・Semi-double: W120 cm × L205 cm (approx. 1,300 g)
・Double: W140 cm × L205 cm (approx. 1,470 g)
Color
Stone gray
Material
・Outer fabric,br>Pile section: 100% polyester,br>Base fabric: 55% polyester, 45% rayon,br>Lining: 100% polyester,br>Pile backing fabric: 94% polyester, 6% polyurethane,br>・Insulation,br>43% plant-based fiber (kapok),br>30% polyester,br>20% acrylic
This winter,
experience ultimate warmth
with a single layer