Off the shelf gear is never perfect, unless you're that mythical "average" size. Even then, there may be features you don't want and ones missing that you would like. Ideally, all gear would be custom made to exact requirements. Of course, you can make it yourself, and many people do this. For most of us, though, this isn't an option, especially with complex items like down sleeping bags. Many companies offer options in length and sometimes width, with a variety of features available. But finding a bag the right size with just the features you want, no more or less, can still be difficult. Enter British company PHD and its Design Your Own Sleeping Bag online program. This offers a huge array of options (at least seventeen, depending on the basic style) and is well-designed and easy to use. The bags use the latest, lightest materials and top quality down.
Using this feature, I designed a bag which PHD then made for me. Below, I describe how the process went, what the resulting bag is like, and how it performs. PHD uses metric measurements throughout, and I have followed this. You will need to be familiar with metric weights and measures to use the facility or else have a calculator handy.
PHD is a small, specialist down sleeping bag and clothing company based in northern England, where all the products are made. PHD stands for Pete Hutchinson Designs. Founder and owner Pete Hutchinson has been involved in producing top quality down gear for mountaineering and polar expeditions, including many to Everest, since the 1960s (he founded the UK company Mountain Equipment in the 1970s). PHD's standard sleeping bags are excellent - I've used several of them in recent years, especially the ultralight +5 C/41 F rated 16 ounce/465 gram Minim and the -5 C/+23 F rated 24 ounce/670 gram Minimus.
Choosing the Route
The process starts on the main PHD web page, where you click on the 'Design Your Own Sleeping Bag' box at the top of their home page. This takes you to an intro page with a dramatic snowy mountain scene, accompanied by the sound of a rushing chill-inducing wind and some atmospheric flute music. This only lasts seconds but can be skipped. This leads into the opening page, which tells you that there are two design routes, a free route for the experienced, who have used sleeping bags and understand their design, and a guided route for those who need assistance.
The opening Design Your Own Bag page.
The first choice: free or guided?
The Guided Route
Select the Guided Route and a page opens to enter the minimum temperature you expect to the bag to handle. This brings up a selection of PHD bags close to that rating. Change the temperature and the selection changes. The weight and price of the bags are given, along with their categorization as ultralight, which means few features, or hi-tech, which means many features. Continuing in the Guided Route allows you to modify these standard designs. Click on one of the bags and a page comes up with information and details. Click on 'Choose This Bag' and the actual design page appears with all the options. These also appear in the Free Route and are described below. In the case of the Minim 400 sleeping bag I chose for this example, after entering -5 C, I added some features which raised the weight and price. It is always possible to go back and change your design if it's not working out as you wish, and you should review the design before submitting an order.
The Guided Route starts with minimum temperature selection.
Having selected a bag, the Guided Route provides the details.
Now the chosen bag can be modified to fit your requirements.
My choices in the Guided Bag Route added 105 grams to the weight and £70 to the cost. I selected a lighter shell fabric, but added a short zip, a collar and waterproof panels in the hood and at the feet.
The Free Route
The Free Route is the one to choose if you know the type of bag you want and don't want to be restricted to modifying an existing PHD bag. The first decision to be made is whether you want a lightweight style or hi-tech style bag. Full details of each are provided. The lightweight style is a simple design with an open hood (which means a zipper isn't essential) and box wall baffles. The high-tech style has trapezoidal baffles, vertical channels over the chest, side channels and a close-fitting mummy hood that doesn't open wide. PHD says hi-tech bags are for extreme expedition use and high altitudes. For most backpackers the extra weight of a high-tech bag is probably not justified. I certainly wanted the lightest bag possible for the minimum temperature rating and so chose the lightweight option. As an exercise, I also designed a hi-tech bag with the same fill and shell fabrics as the lightweight bag described below. It weighed 364 grams more and cost £83 more, both substantial increases, but the minimum rating was the same.
Lightweight or Hi-Tech? The first choice on the Free Route.
Once a choice has been made between lightweight and hi-tech, the next decision is the amount and quality of the down. The possible quantity of down runs from 200 to 1300 grams in 50 gram increments and 700, 800 and 900 fill power down is available. If you're not sure what the differences between these are, or how much down you need, you can click on 'view important information about this option,' and a pop-up chart appears showing you the temperature ratings for different quantities and qualities of down. Bags can be designed with minimum temperature ratings from +7 C/45 F to an astonishingly cold -64 C/-83 F. Sensible warnings point out that this is only a rough guide and that many factors need to be taken into account, both subjective (metabolism, tiredness, food and drink) and objective (humidity, wind, sleeping pad, clothing, altitude). I wanted a bag that would keep me warm down to around -5 C. The 400 grams of 800 fill power down had this rating but the same amount of 900 fill power down had a -8 C rating. That little extra touch of warmth with no increase in weight sounded appealing, so I chose the 900. No choice is fixed however; you can always change it later on in light of the weight, cost, or temperature rating of the bag.
Choosing the down.
Insulation Quantity/Maximum Temperature chart.
Once the quantity and quality of the down has been chosen, you move onto choosing the details. The next page shows the basic bag with the price, weight, and temperature rating. Each time you make a decision that affects any of these, they change so you can keep a precise track of them and go back if necessary. There are seventeen different options covering outer and inner fabrics, color, stuff pattern, zippers, hood, down fill power and weight, down overfill, collar, inner panels, side baffles, hood and collar cords, bivvy cowl, length, and width. With all these options, there are explanations and definitions to help with your decisions. The number of permutations is enormous and fun can be had changing them and watching how the weight, temperature rating, and price change. Here's a rundown of the options, their usefulness, which ones I chose, and why.
Inputting the design.
Four shell fabrics are available. M1 is a microfiber weighing 42 grams per square meter (g/m2). MX is an ultralight ripstop nylon weighing 30 g/m2. Both are highly breathable, downproof, wind resistant, and fast drying. Drishell is 48 g/m2 ripstop nylon with an ultralight coating. The seams aren't waterproof, but the fabric is water resistant, and it's still very breathable. The fourth choice is 70 g/m2 Gore-Tex with fully taped seams. This shell is fully waterproof and lowers the bag's minimum temperature rating to -13 C, but it also adds considerable weight, (the bag weighing 870 grams as opposed to 640 grams for one with an MX shell) and price (£381 as opposed to £259 for the MX). The Drishell outer would be a good choice for use with tarps in damp climates. The Gore-Tex shell might be useful on polar expeditions or alpine climbing, but is too heavy for backpacking, in my opinion.
I prefer highly breathable ultralight sleeping bag shells so the down can loft fully and body moisture can escape quickly, so I chose the MX shell, as it's the lightest. I rely on my shelter, whether bivvy bag, tarp, or tent, to keep off rain.
The choices for inner fabric are MI, MX, Drishell, and 54 g/m2 Pertex, which is the least expensive, but also the heaviest fabric. Again I chose MX.
The choice in colors is not great. Drishell has most with four - red, black, blue, and gold. For M1 and Gore-Tex, the choice is red or black. For MX and Pertex it's the old Henry Ford choice - black, black, or black. Luckily, I like black for sleeping bags, as it absorbs heat and dries fast when aired in the sun.
This is an interesting option that allows you to have the down redistributed so there is more on the top, base, or foot of the bag. In a standard PHD bag, the down is distributed almost equally, with just marginally more over the chest and at the foot. Obviously if you have more down in one area there will be less everywhere else, reducing the overall warmth of the bag (PHD doesn't say how much down is redistributed). However, if you suffer from cold feet (a common complaint) or a cold chest, then having more down in the foot or on top could be useful. If choosing this option, I would start with a bag rated for colder temperatures than I expected so that even with less down in some areas it should still be warm enough. However, as I don't generally feel particularly cold in any one area, I chose the standard stuff pattern.
Zips can be on the right or left side, long or short, with single or double draft tubes. I was interested to see just how much weight a zip and draft tube adds - 150 grams for full length zip with double draft tube, 120 grams for full length zip with single draft tube, 65 grams for short zip with double draft tube and 55 grams for short zip with single draft tube. I avoided any extra weight by opting for no zip at all. This reduces ventilation options, but that's not something I've ever found to be a big problem.
The choice is between an open hood, which can be tightened around the head when needed but which allows good ventilation when fully open, and a mummy hood, which always fits close round the face. The bag has to have a zip to have a mummy hood, so I'd have had to go back and choose a zip if I wanted one. I prefer an open hood anyway, as it's more versatile.
After confirming or changing the amount and quality of the down, there's an option for putting extra down into the shell so the down is packed more tightly. PHD points out that they optimize the amount of fill and the shell size, and that an overfilled shell doesn't have as good a warmth to weight ratio, but some people like a thicker feeling bag, and it reduces the chance of thin areas appearing due to the down shifting as you move in the bag. A better warmth to weight ratio can be had by increasing the standard amount of down in the previous step or the quality if 700 or 800 fill power down has been chosen. The amount of down overfill is 100 grams. If chosen this would have lowered the minimum temperature rating of my bag from -8 C to -11 C. However, if I'd increased the amount of down by 100 grams and had a shell sized to go with this, the rating would have been -14 C at a weight increase of 15 grams over the overfilled bag.
This is a simple option: to have a collar or not. I chose not, as one adds 60 grams of weight, and I don't like collars much anyway, as they restrict ventilation and don't seem to make much difference in warmth.
Water resistant panels in the hood and the foot can protect the down against moisture from your breath or dampness from socks. I've used bags with these, and they do work, especially the one in the hood. I haven't had serious problems without them however. PHD's Drishell panels only added 10 grams (and £15 in cost) so it was tempting to add them. However I wanted the lightest bag for the warmth, so I resisted.
Side baffles prevent the down from shifting from top to bottom and vice versa. In bags without them, you can shift down from one side to the other to increase or decrease the warmth. If, that is, you can keep that side on top. Those who turn in their sleep and often wake with the bottom of the bag on top, as I do, learn that no side baffles can mean waking in the early hours with a cold back as the down has shifted. That is my one complaint with PHD's off the shelf ultralight bags - they don't have side baffles - and a main reason why this design option is of value to me. So I chose the side baffles, despite the 10 gram weight increase - my only concession to a feature that added weight.
Hood and Collar Cords
The choice here is between stretch and non-stretch. Having used both, I find non-stretch hood cords easier to use and less likely to allow the hood to gape, letting in cold air. If I'd chosen a collar, I'd have gone for a stretch cord, as these give when you move, making them less restrictive than collars with non-stretch cords.
This is a curious option that is basically the top half of a bivvy bag. It's made from proofed nylon and lies under the bag when not needed. Pulled up it covers the head and body down to the chest. There's an elastic drawcord in the hem but no zip. The seams aren't sealed, so it's not fully waterproof. PHD says it's for below freezing conditions, not rain. In combination with a bag with a waterproof shell, I guess you could sit out a blizzard on a ledge during a climb with this, but I don't think it's of great interest for backpacking. It adds 100 grams to the weight and £37 to the cost.
Length and Width
Being able to choose from five lengths and four widths is one of the great benefits of PHD's Design Your Own Bag, as many people find the choices in off the shelf bags too limited and end up with bags that are too long, too short, too wide or too narrow. In lightweight bags, PHD offers lengths for people up to 142 centimeters/62 inches (X-Short), 168 centimeters/66 inches (Short), 183 centimeters/72 inches (Standard), 198 centimeters/78 inches (Long) and 213 centimeters/84 inches (X-Long). Being 5'8", I chose the Standard length. The widths refer to the maximum torso circumference, whether the chest or waist. The options are up to 92 centimeters/36 inches (Slim), 109 centimeters/43 inches (Standard), 121 centimeters/48 inches (Wide) and 135 centimeters/53 inches (X-Wide). Again, I chose the Standard width. (For some reason, PHD gives English and metric measurements here).
The Final Decision
Once all the decisions have been made and perhaps considered and reconsidered, you can review the bag you have designed and submit your order. Before doing this, you can save a copy of your design and email it to yourself as well. This is done by clicking on the floppy disc image in the lower left corner of the sleeping bag picture. This saves the design and brings up a box in which you can enter your email address and then click to have the design emailed to you. I did this and a few minutes later received an email containing the following:
Your Bag Design
|Min Temp C:||-8|
|Down Fill (g):||400|
Checking the final design.
PHD gives deliver time as twenty-one days in the UK, thirty days outside the UK. Mailing charges are £15 for the UK and the EU and £25 for other countries. My bag arrived in a week, but it was a special order for this article.
The Sleeping Bag
Of course, for the application to be really useful, the end product - the sleeping bag itself - has to fit the design brief. The bag supplied does this perfectly. The dimensions are correct and the weight is 652 grams/23 ounces. The fit is on the slim side, but there is enough room for me to move in the bag and to wear clothing if necessary. The MX fabric is very soft and comfortable, and the bag feels luxurious to sleep in.
The finished bag.
The bag is supplied with a stuffsack weighing 25 grams/0.88 ounces and a big mesh storage bag. The stuffsack measures 30.5 centimeters/12 inches by 18 centimeters/7 inches, which is quite compact for a bag with this rating. It can be compressed to half this size. The stuffsack isn't waterproof, so in wet weather, it will need to be stored in a waterproof pack liner or replaced with a waterproof stuffsack (or both if you want to be really certain it'll stay dry in the pack).
Weight of the bag with stuffsack.
The stuffed bag compared to a 750ml titanium mug.
I haven't yet been able to sleep in the bag at -8 C/17.6 F, as early autumn temperatures in Scotland do not often dip below freezing. At +5 C/41 F, I was very warm with the hood wide open.
Comparable with the PHD bag is Rab's Quantum 400, one of my favorite bags, which weighs 885 grams/31.2 ounces and costs £250. The Quantum 400 has 400 grams/14.1 ounces of 750 fill power down (European measurement)/850 fill power down (American measurement), and is rated to -5 C/23 F. PHD uses the European fill power measurement. However despite the theoretically higher lofting down in the PHD, I measured the loft of both bags as 13 centimeters/5 inches at the chest. The Quantum 400 has a full length zip with a baffle and a collar. If I'd chosen these features for the PHD bag, it would have weighed 830 grams/29.3 ounces and cost £304, still lower in weight but significantly more expensive. The Quantum 400 is slightly longer than the PHD at 215 centimeters/84.6 inches as opposed to 210 centimeters/82.7 inches. The Quantum 400 has kept me warm at -7 C/19.4 F, so I expect the PHD bag to do the same.
The Process Summed Up
The Design Your Own Bag application is easy, quick, and fun to use. All the options are clearly explained, as are the relationships between them when necessary (such as having to have a zipper with a mummy hood). Being able to see how changes affect the weight, temperature rating, and price of the bag, plus the choices you have made, means you are always fully in control of the process and can change any option at any point. This is a very well-designed program. Of course there are many good off the shelf sleeping bags, including those from PHD, and most people find one of these fine. However Design Your Bag provides the opportunity for a customized bag that is exactly what you want and which can solve problems of size for those who don't fit off the shelf bags. I think it's excellent.