Backpacking Light testers got an early look at RBH Designs’ vapor barrier socks back in 2001 when they first came out, and praised their versatility and ability to seal in moisture and warmth. As part of a project on Lightweight Footwear Systems for Snow Travel (to be published soon), we compared the RBH Designs VaprThrm Liner Sock and VaprThrm Insulated Sock with other vapor barrier (VB) sock designs. The Liner Sock (1.8 ounces/pair, size Large) is the lightest one we tested, had the best fit, and was the best performer. The Insulated Sock (4.7 ounces/pair, size Large) is essentially a vapor barrier sock and insulating sock combined, and also performed very well on day trips.
RBH Designs VaprThrm Liner Sock (left) and VaprThrm Insulated Sock (right). For information on the Principles and Techniques for using vapor barrier socks, see the article in the sidebar.
Both RBH Designs vapor barrier socks have a soft lining and are recommend to be worn against the skin. The layering system for the Liner Sock is (left to right) to put the vapor barrier sock on first, then wear a wool sock over it. The Insulating Sock is a vapor barrier sock and insulating sock combined, so it can be worn as a single layer, or with another sock over it for extra warmth in frigid temperatures.
To get the proper sizing for RBH Designs’ socks, the procedure is to trace the outline of your foot on a piece of paper, measure the length and width, match it with a list of sizes on the RBH Designs website, and choose the closest match. Or, order custom socks for an additional $6 charge. This is an excellent system to ensure that the socks fit when you get them.
VaprThrm Liner Sock
The RBH Designs VaprThrm Liner Sock: interior and exterior (left), and worn in the field with gaiters removed for the photo (right).
The Liner Sock is made of a three-layer fabric consisting of a soft brushed tricot lining, a vapor barrier film, and a brushed tricot applied to the outside to protect the membrane. The sock is not seam sealed, but it is an effective VB to seal moisture inside, except for a very small amount of moisture (from sweat) that might move through the seams into an insulating sock worn over it.
The RBH Designs VaprThrm Liner Sock is a three-layer construction consisting of a waterproof film sandwiched between two layers of a soft brushed tricot.
The socks have a semi-fitted design, meaning that they are tailored to the shape of the foot but loose fitting. Wearing an insulating sock (merino wool recommended) over them compresses the VB sock to the foot. We did not feel the folds or have any problem with them rubbing against our feet.
We especially liked the Liner Sock for day use in frigid temperatures (below 25 F), where a VB provides a distinct benefit. They accumulate some moisture inside (from sweat), and their tricot lining minimizes the clammy feeling. Even though there was some moisture within the VB, our feet stayed warm as long as we kept moving.
RBH Desgns VaprThrm Insulated Sock
RBH Desgns VaprThrm Insulated Sock: interior and exterior (left), and worn in the field with gaiters removed for the photo (right).
The Insulated Sock is a VB sock and insulated sock combined, and has the same design and fit as the Liner Sock. These socks are also a three-layer construction, consisting of a soft brushed tricot lining, a vapor barrier film, and a fleece exterior. Both interior and outside fabrics are very durable, so these socks should last a long time.
The RBH Desgns VaprThrm Insulated Sock is also a three-layer construction consisting of a soft brushed tricot lining (thicker than the Liner Sock), a waterproof film, and a fleece exterior.
This sock can be worn as a single layer or with another insulating sock over it for extra warmth. The exterior seems more like felt than fleece, which makes the sock a little heavier than expected. We found them a little more comfortable with a thin liner sock inside them, but that gets down to a matter of personal preference. Since the Insulated Sock is thicker, the seams are thicker and more noticeable when the sock is compressed inside a boot. We did not have any problems with the seams rubbing our feet, but we found that the Insulated Sock is less comfortable to wear compared to the Liner Sock with a wool sock over it.
With either of the RBH Socks, there is no question about the warmth this VB sock system provides in frigid weather. For the ultimate warmth, a dynamite layering combination is the Liner Sock, wool sock, and another VB liner or the Insulated Sock over that.
The Insulated Sock performed well on day trips, where they can be dried out at home overnight. However, when we used the Insulated Sock on multi-day trips in frigid temperatures, we had a problem with the thicker inside lining absorbing moisture during the day and being more difficult to dry out at night. When snow camping is involved, a better VB sock system would be the RBH Liner Sock plus a wool sock, or the double VB system described above.
Features and Specifications
- Manufacturer: RBH Designs (www. rbhdesigns.com)
- Sizes: 5-13, match your foot dimensions to available sizes on the RBH website, or order a custom size
- Fabric: Liner Sock is brushed taffeta sandwiching a VB film; Insulated Sock is thicker brushed taffeta on the inside, VB film, and fleece on the outside
- Features: Semi-fitted, sewn-in sole panel
- Weight: Liner Sock measured weight size Small 1.6 oz/pair (45 g), size Large 1.8 oz/pair (51 g); manufacturer specification 1.8 oz/pair (51 g); Insulated Sock measured weight size Small 4.0 oz/pair (113 g), size Large 4.7 oz/pair (133 g); manufacturer specification 4.8 oz/pair (136 g)
- MSRP: Liner Sock $26 US, Insulated Sock $36 US