40° Nano Blanket

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Nano Blankets are specialist tools with room for broader appeal.

40° rating, super compact stuffed size, ultralight. Versatile, essential, inspiring. SUL.

Extensive custom options are offered to dial in critical details. 

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In it's basic rendition the 40° Nano is a tapered rectangular backcountry comforter made with gossamer light fabrics and high fill power goose down.

It is as light and compact as is currently possible. All clutter has been removed. In this configuration there's no Velcro, no shockcords, no snaps. Only pure function remain: 10d Membrane shell and liner. ¾" box baffled construction. 900 FP down. 

Stepping up in features from the comforter mode gradually creates a more enclosed, all-round blanket, but still based around the original minimalist mindset and 40° rating. Shockcord channels can be added at the foot end or top end, or both. Using specially sourced 1/16" shockcord and minimalist cord locks each channel adds about 12 grams, depending on blanket width. 

To control the foot-end one can add an ultralight sleeve designed to contain the sleeping and/or the user's feet.

Underbody control cords used to cinch the blanket tight and seal out drafts is also an option. However, in a nod to SUL philosophies, these are merely comprised of 1/16" shockcord and tiny captive cordlocks. 


The Nano Blanket is custom built with 8 lengths and 5 shoulder widths available in any combination. Add to this three foot end sizes. And, if these 120 sizes are not sufficient for you - just email 

Fabric Technology

The Nano Blanket is offered with either highly breathable shells or less permeable ultralight waterproof/breathable materials.

The breathable option is fast drying, comfortable and saves a few grams in finished weight.

The waterproof/breathable shell is ideal for severe conditions or 'survival' use. With the Nano Blankets fully reversible design one can either face the shell towards the elements to ward off mist, spray and dew in an open bivy or brief recovery stop; or face it in towards the body to achieve a mild Vapor Barrier effect. This will keep moisture from damp sweaty clothes from migrating into the down, and will also boost the temperature rating of the Nano by a few degrees. Adventure racers and endurance bike riders will appreciate this fast and simple method of quickly resting without compromising the insulation.

Among the breathable options is a Pertex Quantum shell fabric in Mountain Safety Orange, for applications where ultimate hi-viz is desirable.

Down Type

Select 900 fill power down for lightest weight and bulk. Only goose down used - responsibly sourced and of the highest quality. Choose between regular and Hyper-Dry moisture resistant varieties.

The silnylon stuff sack supplied is 11-16 grams.

Possible uses for Nano Blankets:

Boost-liner for old tired mummy bags.

Emergency or planned bivys.

Recovery/rest blanket for: Ultra running, FKT attempts, adventure racing.

Warm-up blanket for backcountry skiing and other winter activities.

Home or camping comforter.

Safety net for committing day hikes.

Summit day just-in-case bivy.

Backcountry trauma/shock control.

Hammock underquilt (with some user mods!)


The tables below outline the total weight of the bare bones Nano blanket. The optional features available in the configuration menu include an estimate of how much they increase the weight.

All the numbers are subject to change and include a 5% margin of error.

The silnylon stuff sack supplied is 11-16 grams.

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40° Nano Blanket

40° Nano Blanket

Nano Blankets are specialist tools with room for broader appeal.

40° rating, super compact stuffed size, ultralight. Versatile, essential, inspiring. SUL.

Extensive custom options are offered to dial in critical details. 

Product Options
Temperature Rating
Overall Length
Length of blanket lying flat with any (optional) closures undone.
If choosing end closures add 5-10" to the length here to make up for the bunching and shortening that occurs when drawing the ends closed. The wider the blanket the more extra length you need.
Shoulder Width
The width across the blanket at the top to about 3' down, with any (optional) closures undone
Foot End Width
The width across the blanket at the foot end, with any (optional) closures undone
Top End Closure
A standard quilt style drawcord across the top hem is the option here, and adds 14 grams depending on the width.
Elastic Drawcord in Channel, adds 12-14g
Foot End Closure
This upgrade equips the Nano Blanket with a more thermally efficient foot area.
It consists of a simple shockcord to gather up the end, and adds about 12 grams.

Elastic Drawcord in Channel, adds 10-14g
Foot End Sleeve for Ground Pad
A 24" deep sleeve for inserting the foot end of a ground pad. This is a way of making a really narrow foot section more thermally efficient. Can also add utility without the use of a pad.
It can be combined with the foot drawcord option above for further control.
Adds about ounce. The silnylon option is tougher, while the Membrane is the lightest.
No Thanks!
Silnylon Sleeve, adds 20-25g
Membrane Sleeve, adds 12-16g
Shell Fabric

Please see our Fabric Page for help choosing the right shell material.

Liner Fabric
10d Black Taffeta - Lightest, most breathable
Strap Package
This option adds 4 grams of non-removable hardware. The shock cords are an additional 6g
Down Type
Choosing Hyper-Dry moisture resistant down will help combat the effects of perspiration, misting tents and damp air. Nunatak products made with Hyper-Dry down will have a slight increase in bulk over those made with regular down. In some instances they may contain an additional 5% of fill weight.
Down Overfill
Adding overfill can prolong the life of the down, help maintain loft during moist conditions, boost the temperature rating by a small amount and keep the down volume from shifting. Expect a weight increase ranging from one to six ounces depending on the product, the size and the rating.
No Overfill
Overfill focused on foot section
Overfill focused on torso section
Overfill evenly distributed throughout
Plus quantity overfill evenly distributed
Stuff Sack
Our stuff sacks are pretty dope, but current weight saving trends in ultralight circles eschews this once crucial item. So, opt out and save $ while also being very current.
Yes, please include a stuff sack
No stuff sack