Stephenson's Warmlite

 Index |



Weights | Comfort Ranges | Prices | Down Air Mattress

The WARMLITE TRIPLE bag is the only complete backpacking BED for ALL temperature ranges, providing comfort in all conditions anywhere, in THREE overlapping temperature ranges from +60° to -60°F (-75°F to -80°F reported by hardy Alaskans). An optional net top extends use to the tropics.
A WARMLITE bag gives best COMFORT, warmth, adjustability, and least weight, thru good design, superior fabrication, and efficient use of best materials. Multi tops for all conditions and a very comfortable insulating mat block ALL types of heat loss: convection, conduction, evaporation and radiation. We’ve long expected others to copy our features to make better bags, but most unique advantages of even our 1959 bags and many improvements since, are still only available on WARMLITE bags.
INSULATION: CONVECTION heat loss: blocked by windtight ripstop nylon, double zippers (since 1957), closely fitted collar and fully adjustable hood (since 1958). Air can’t enter to carry away heat (unless you adjust it to).
CONDUCTION heat loss: blocked by highest loft 820-890 GOOSE Down available, held in a very uniform thickness not affected by your position in the bag. The bag is shaped for least surface area consistent with comfort. Follow our girth measuring instructions to select bag for best comfort. 3" to 4" less girth gives less weight but restricts motion, like a mummy bag, which few can tolerate: less girth isn’t practical for anyone.
EVAPORATION heat loss is blocked by flannel like soft vapor barrier (VB) fabric on bottom and collars, and your choice of VB fabric on interior of the tops. With collars snugly closed you get up to 15° more warmth from the VB. Open the collars and humidity escapes, removing the extra warmth. VB aids temperature control by giving extra warmth only when needed. We’ve used VB since 1955, and all Stephenson bags have had VB since 1968, a major reason for enthusiasm of users. The VB is as “breathable” as Goretex (as defined by their level of humidity transfer), and thus an excellent vapor barrier for this use.

Other VB gains:


(Size 56”,60”,64” and 70” on DAM Refers to the girth size of sleeping bag it fits into)

Heat loss to ground: is blocked with a 3" to 4" thick, full size 1 1/2lb. Goose Down filled Air Mat (used since 1975), for the soft comfort & light weight of an airmat (which is usually cold), and WARMTH of Goose Down (in other bags Down is destroyed by lying ON it): no bulk and weight of covered foam pads (or those heavier “self inflating” foam cored airmats.) For less cost +1 lb. & much more bulk get the 2" thick foam pad option (used since 1966), still lighter and more compact than “self inflating” foam airmats. With pad locked to the bag you won’t roll off, or turn your insulation into pieces of cold non-insulating string by lying on it. To use either DAM or Foam in the bottom, order DAM bottom bag plus Foam pad (the DAM of proper size won’t fit a bag made for foam pad only.) The wider foam pad to fit in DAM space is ½ lb. heavier than normal foam pad, needs larger carry sack.
We made the first Down filled airmat in 1959, learned to produce them in 1975. Net baffles block Down shift. Fabric is very tough heat sealable coated nylon taffeta, the strongest used in any airmats. Performance exceeds all expectations, with life over 20 years. Color: yellow or orange for emergency use to attract attention. It can be used for a swim or fishing float or, will float the bag when the creek rises and floods your camp. It inflates fast with the carry sack used as a pump, (never by mouth or slow heavy pump.)

RADIANT heat can be reduced by aluminized upper surface facing the DOWN on inside top fabric. This was standard since 1968, will be optional soon. Radiation loss is greatly reduced when inside a tent or under heavy foliage, so you may not need aluminizing. The silicone coated nylon used on our tents is a better vapor barrier, more durable than the aluminized urethane coated nylon, so is offered as an option, and will be standard when urethane fabric is gone. Vap-R-Soft option is aluminized, but that will end when material is gone (cost too much, no longer made). The aluminized silicone nylon can be used, adds $50.
After trying about every possible foot end design we found that the simple extended foot space was best, allowing your feet to relax in normal position no matter how you sleep in the bag. Other “contoured” or fitted foot ends all restrict foot spread and are uncomfortable for sleeping on your side or stomach.


Even at the zippers there’s no insulation loss: Parallel zippers separately close inner and outer surfaces. Separating zips on each side, and across the foot give independent venting and let you zip bags together on EITHER side, or join the tops together for a very wide warmth adjusting top. Use tops zipped together for a quilt on your cabin bed. In very cold conditions, to dress INSIDE or for fine tuning from -50° to +10°, using both tops, unzip tops on opposite sides to let the bag expand as needed.
In 1987 we advanced to the excellent YKK #3 zippers for bags, for least weight, least snags. Experience with #3 on bags since 1987 has been as flawless as on tents since 1970. Heavy zips used by others snag fabric (which spreads the slider and makes zipper come apart).

FULLY Adjustable HOOD

The unique Warmlite hood design evolved as a way to permit full head protection when sleeping in any position. Most hoods can only be closed if you lie on your back. Our hood zips up over the shoulders and snugs up over or around the head with the top drawstring, so can close snugly around your face or nose when you’re on your back, or adjusts to cover your head and leave breathing space when lying on your side or stomach. It is not the easiest hood to close, but it IS the most adjustable.
For safety we use non lock zip sliders; if you wake with your head in the bag, a good push will open the hood. Velcro tabs across the zippers at two positions take more than usual force to pass, so they won’t drift open. You can add tabs for more positions if desired.


The standard Warmlite Triple includes both the THIN (1.8" thickness= 3.6" “loft”) and THICK (3.8" thickness= 7.6" “loft”) removable tops (equivalent to 11.2" loft combined), attached with parallel rows of separating zippers along each side and across the foot, so there can be no cold zipper line when THICK or BOTH tops are used. Usually the THIN top is used down to 25° (summer range), the THICK top down to -10°, and the combination for quick warmup, or winter use down to -60° F. (- 75 to -80 reported by hardy Alaskans!)
Comfort ranges are greater than for any other bag of similar thickness due to controllable warmth of vapor barrier. Uniform thickness and dual zips let you move as you wish and stay warm, so you won’t get stiff and sore from staying in one position all night. (If you’ve experienced cold nights in bags with separate pads, you know how any attempt to roll over makes you COLD when crushed insulation below is exposed: you soon learn “don’t move”, then wake up stiff & sore.)
For tropics, use the optional NET top, a double layer of fine noseeum net held 3/4" apart with many foam spacers. Bugs on outer layer can’t reach thru to you, (but you will want repellent near your head: if you hear them close you can’t tell if they’re inside or out!) When it’s cool enough to wear some clothing, just use repellent, as you do during the day.

For use outside a good shelter, spray on water repellent recently applied is best for dew or drip protection. Bags without VB always get wet from the INSIDE humidity condensing in the insulation, even with no outer cover. ANY material (“breathable” or not) laid over ANY sleeping bag greatly increases condensation even with VB. Goretex (which is as good a vapor BARRIER as urethane coatings), was removed from use on bag exteriors because it CAUSED the bags to ALWAYS get WET. “Driloft” replacement is justified “because it only gets the bags half as wet”. I prefer a DRY bag! Don’t put any waterproof cover or bivy sack over any bag you want to keep dry!

A 1 mil. plastic drop cloth works best for ground protection, plus gives an area for your pack, boots and other gear. (note that we sell WP covers and bivys because dumb people demand them, not because they make any sense!)


Since 1968 we’ve used aluminized urethane coated nylon for radiant heat blocking and vapor barrier interior. That is standard on tops until supply is gone. Then the silicone coated nylon now an option) will be standard for best VB, least weight, best durability, and many colors. For $50 extra you can have aluminized silicone fabric on interior top.
The bottom interior is FUZZY STUFF, a very comfortable brushed knit Nylon plus tough stretchy urethane film. It wears much better than coated fabric, is best for comfortable long life sleeping bag inside bottom, VB sox, glove liners and clothes. The surface feels like soft flannel, but wicks sweat across it’s surface even faster for rapid drying and comfort. It’s worked great for our boat cushions in BVI since 1990: comfortable to sit on nude, quick to dry. FUZZY STUFF is so comfortable against your skin you won’t want to wear anything under it.
FUZZY STUFF is used on bag bottom interior where comfort, extra wear resistance, wickability for fast drying, and easy cleaning is needed, but not on tops: it clings slightly to clothing, weighs more, and more toughness isn’t needed on tops. Colors vary: we try to pick compatible interior colors. Send stamped addressed envelope for samples.
EXTERIOR fabric is the finest 30 denier Down proof ripstop nylon with soft, water repellent finish. Used since 1958 without failure, it’s obviously TOO durable, but there’s no lighter Down proof fabric! Every part is HOT CUT, the ONLY way to keep seams together. All others hide raw knife cut edges with binding tape or flat felled seams, but that won’t keep them from soon pulling apart. Usual colors are red, blue, or green, some others for special orders.
Each bag is individually sewn by a highly skilled person working at home. The highest loft most mature Goose Down available is carefully HAND weighted into each pocket, in a sequence that assures designed uniform loft.
Contoured direct tension vertical baffles, closely spaced, maintain uniform loft no matter how you move in the bag, yet allow CONTROL of insulation: if too warm, pat and force the Down out to sides to thin the center. If cold, gently pat from inside, expanding Down to fill tubes for more warmth.
All sewing is with 100% Nylon thread to match fabric strength, stretch, softness and super wear resistance. (Cotton or polyester thread make stiff seams which don’t wear well.)

The cost of a WARMLITE TRIPLE seems high because it includes so much. Compare it to other bag combinations needed to match it: winter bag + summer bag + overbag + VB liner +4 lbs. of 2 self inflating pads to match warmth and comfort of D.A.M. You’ll find they add up to MUCH more cost, weight, and bulk. We give you more for your $ by avoiding duplication of materials, low overhead, no sales markup, and sometimes no profit.
Many people don’t need extreme low temperature capability of a full TRIPLE bag, but want something for 3 season use where it might range from 10° to 65° F. The WARMLITE TRIPLE is ideal for that use, while no other single bag can cover such a wide range. The thin top covers 25° to 65° range, the THICK top -10° to 45° range, and the combination gives quick warmups (and warmth enough for surprise emergencies down to -60° F. for average person.) Why buy 2 or 3 other bags to cover the range, not know which to take, or worse, find you’ve taken the wrong one, when one WARMLITE does it all?
When we made all tops removable on TRIPLE bags in 1970, purchases of our single top bags dwindled to nothing, so we stopped listing them (but every 2 or 3 years someone requests a special single top bag, which we make for him). In the past a couple of others copied our multi top bags (& humorously claimed to have invented the idea), but left out the VB and thus failed. All other bags sold are still only for single condition use and need another whole bag to extend range. People buy limited use single top bags to save money, but when another bag is needed for other conditions, the cost doubles. Weather is NOT predictable. A non adjustable bag can leave you dangerously cold or miserably sweaty. With a WARMLITE TRIPLE you get best materials and features, and the effect of 3 bags and pad with complete weight of only 1 1/4 bags. In any form it’s lighter, more compact than any other equivalent single bag and pad. Leave thick top home, save 2+ lbs. Leave thin top, save 1+ lb.
We’ll custom make thinner lighter Triples and special Single top bags if really needed, but expect alternate suggestions from us if our experience indicates your stated needs will be better met with something different. We rather have you happy for many YEARS from now, not just pleased with us before you get it!
WARMLITE bags are stocked (when we can) in 4 girths with “standard” heights, in red, blue or green. We will make them TO ORDER for ANY height, ANY girth, any colors we can get (or combinations). When ordering give us YOUR height and weight, girth measurement (see measuring sketch), desired bag girth (and WHY if different from measurement), whether you’ll take standard height bags for that girth or want it custom made to your height (to save 1 oz./inch), type of bottom pad (D.A.M. or FOAM), and color choice(s). If rushed, call to check stock. Production may take 4 to 12 weeks.

Typical TRIPLE Bag Sizes and Weights relative to height (hgts) and weight (wghts) of users:

 Typical TRIPLE Bag Sizes and Weights







5' - 5-8" 

5'4" - 5'10"

5'8" - 6'4"

5'10" - 7'


90 - 120

105 - 155

130 - 190

170 - 250

Typical weights for each layer in ounces: (excluding Pad)


























 Total w/dam





 Foam Pad





 Total w/foam





How to Measure Girth

Note: Layers are filled for given LOFT, not weight, thus when Down loft is better these weights will be less, and vice versa. Decrease in height reduces weight about 1 oz. per inch.

Bag Packed Sizes

 WITH Down Air Mattress...

10" x 27"

WITH Foam Pad.................

11" x 27"


Additional info and most asked questions:

Life of insulation. If you lie on the insulation in your sleeping bag or parka, and then move sideways to turn over, you put shearing force on the insulation. That tears synthetic insulations, and rolls Down into pieces of “string” from which it will never recover. Stuffing your bag or parka does the same thing, plus puts excessive loads on seams. Prior to 1966 we had people bring 2 to 3 year old bags in to restore loft, and we found the lost loft was entirely due to “strings” of Down caused by lying on it. Since 1966 our bags with pads IN them have never had that problem. If you are using a bag loose on a separate pad, put some straps on the bag bottom to hold it securely to the pad, and shift as much of the Down out to sides and top as you can so you won’t lie on it. To pack a bag, always carefully fold and roll it. Uniform end compression of the roll to fit in a sack won’t harm it. Don’t stuff anything you don’t want to rapidly destroy!
Washing and drying Down: A simple test will show that equal dry thickness of Down will dry much faster than synthetics. As Down dries from the surface, interior moisture wicks to the surface where it has access to dry air and heat for rapid evaporation. With synthetics the surface lofts and insulates the interior so it takes much longer to get the needed heat in and the water out. BUT, if you saturate a Down bag and let the Down all clump together, drying will take much longer: you have greatly reduced surface area and greatly increased thickness to be dried. Thus the stories of Down being slow to dry! Those stories are correct when you put them in context. Wool is similar to Down in wicking ability and moisture holding, but being available only in dense heavy woven form it doesn’t compress as it gets wet (it’s already compressed). Both Down and wool can absorb many times their weight, within the fibers, with no effect on insulating ability. Add more than about 5 times their dry weight and Down starts to collapse and lose insulating ability, while air spaces in wool fill up and you lose insulating ability. In each case people get misled, not realizing how close to total collapse their nice Down bag is after 5 or 6 nights without inside vapor barrier, or thinking their wool shirt can continue to keep them warm without rain gear.
A common misconception is that rainy weather means high humidity. Observe how all that dense summer haze disappears after a rain storm. Rain is COLD, formed at cold high altitude, and acts as a dehumidifier as it falls thru lower levels. Where there is regular rain and overcast (as in the NW) the humidity stays low most of the time, and that dry air flowing over the mountains causes desert conditions to the east. In the SE, quick storms soak everything and then intense sun evaporates that water, causing 100% humidity and continous haze (thus the Smoky mountains).
We often hear of people using short or narrow pads to save weight. When sleeping you need MORE insulation at your feet since you are no longer producing lots of excess heat in your legs and feet as you do when hiking. If your pad isn’t wide enough to support your arms when on your back you won’t be able to stay comfortable and won’t sleep well. It’s good to minimize weight, but you can carry much more IF you get a good comfortable night’s sleep.
I often hear people saying they can be warm and comfortable with an ultralight thin bag and thin closed cell foam pad, when they are asking why we can’t make our bags lighter. It should be obvious that the reason they are spending $$$ to talk to me on the phone is that they have NOT been warm or comfortable with that inadequate gear! They want and need warmth and comfort, then expect that since we have already done so much better than anyone else, a simple request should make us do even better just for them. I wish it was so, and appreciate the compliment, but we don’t do miracles, and when we find a better way it will be for everyone. BUT, there are practical modifications that can be made for special or limited uses, so don’t be too bashful to ask for such. We can and do make single top bags, special contoured bags, lighter fill for warmer conditions. Just don’t ask for a bag bigger, thicker, AND lighter, or for one without VB. Also all orders for delivery yesterday must be in before noon tomorrow (or, “you wanted it WHEN”).

Polyester fiberfill is usually the lightest practical insulation per inch for clothing. Good Goose Down is much lighter, but weight of extra fabric used in construction usually offsets the reduced insulation weight. Only in the very thick insulation needed for sleeping bags is the great advantage of Goose Down really important. We are regularly told that such and such synthetic fiberfill is “as good as Down and much cheaper”. But when you compare numbers, for same insulation they are ALL much heavier than good Down bags, yet cost as much. Are they lying? Not quite: Poor duck Down can have loft as low as 200 per lb. while best fiberfills can have initial loft of 200 to 300. The rub though is that synthetics lose that initial loft rapidly from lying on it and packing it. Thus they can be as good as worst Down when new, never anywhere near as good as good Down.