Layering: I have been in the outdoor industry for quite some time now and I would like to make a contribution so that you all can stay nice and warm this winter. Be ready for some education. Layering concepts have been around since the beginning of time. There have always been 3 main ingredients to layering. Base, insulation and shell are the primary ingredients to layering. Here are the definitions to each: Base-The base layer is designed to wick sweat and transfer the moisture out to the insulation layer. The materials used for absorbsion are typically synthetic hydrophobic fabric. This means that the material will only absorb the moisture to transfer it without retaining any of the water. The fabrics available today have a very quick drying ability, which in turn will make you feel very comfortable and keep you warm. The best materials used are polyesters rather than polypropylene. Polypropylene (or polypro) has a reaction to odors and typically retains odors even after washing. Polyesters are mush more resistant to water saturation and odor retention than polypro. Contrary to popular thoughts, polypro isn’t used very often in base layers even though people still call base layers polypro. The best base layers I have found are very thin yet still transfer and dry quickly. Here are a few choices; Patagonia silk weight layers, Smartwool aero layers, Sporthill energy layers. Remember that if you use anything other than polyesters (or wool blends), the fabric will retain water which will in turn conduct cooler air and make you cold regardless of how much insulation you are wearing. Cotton is the main culprit. Insulation-Insulations vary from thin (2mm) to very thick (3”). The primary function of insulation is to trap the warm air that your body produces and retain the warm air for as long as possible. Insulation thickness directly relates to warmth factor. The other function to insulation is to transfer moisture produced from your sweat to the outside air while still retaining the warm air that is produced from your core temperature. Insulation layers are typically a type pile or fleece but can also be a lofting material. Insulation layers can also range from the following layer from your base layer to the very last layer that you are wearing. There is a formula for insulation by varying thickness of fleece designed from the Malden Mills Company, which are the primary textile manufacturers of fleece. They label their fleece Polartec. Weights are from 100 to 300 weight. 100 weight fleece is the thinnest and will typically do the best job in wicking the base layer moisture to the next layer of either insulation or wind/waterproof shell material. 200-weight fleece is the most popular insulation layer because of its wide temperate range. 300-weight fleece is the warmest pile material available from any manufacturing company. This weight is typically for very cold temperatures. All 3 weight have some common ground, they are all very breathable which means the material can insulate when damp, can transfer moisture from sweat the fastest and is very light in actual weight. The downside to fleece is its compressibility. Packing a fleece jacket is difficult for it’s insulation value. Also remember that if the insulation layer is windproof, it will not transfer moisture at the same rate as a non-windproof pile fleece. Typically windproof pile retains more moisture than non-windproof fleece, which can make you colder as well. The only other type of insulation is down. Down has the greatest warmth value for its pack ability and weight. It can also be used in varying ways as the next layer from your base layer, to the very last layer in your layering system. This factor is quite different than fleece because down can also be worn over your shell layer. Down can not retain trapped warm air when wet and looses it’s insulation value when wet. The fabrics that retain the down vary from very breathable nylons to not so breathable yet waterproof laminates depending on how it is used in your layering system. Shells- Shells are your very last layer. It can be water-resistant, wind-resistant or insulating or all three. To determine what you need most from your shell, you must decide which is more important; water-resistant, wind-resistant, insulating or all of the above. The most common way to use a shell layer is to only combine the water and wind-resistancy or possibly water and wind-proofness. This layer varies the most and you will have the most amount of options depending on how necessary each factor is. Typically, waterproof shells are also windproof but not vise versa. In warmer climates (45 to 55 degrees), you will only need a base layer and a windproof shell. In wet and warm climates (45 to 55 degrees), you will only need a base layer and a waterproof shell. As the conditions change, you will need to add and subtract insulating layers to regulate your core temperature. The most popular waterproof shell materials are nylon and polyester with a PTFE laminate. PTFE is a Teflon based material, which can bond to nylon and polyester to provide a waterproof yet breathable material. The rate of breath-ability is based on its water-proofness. The more waterproof, the less breathable and vise versa. Gore-Tex is the main manufacturer in the US for waterproof/breathable laminates but Gore-Tex isn’t always the best. Sometimes you will only need very little water and rain protection but will need much more insulation. This is where a nice and thin windproof shell that is very breathable will work better. Your sweat will evaporate at a much greater level if it is not trapped under a laminated nylon which can in turn, make you much warmer. If it is not raining, you should be more concerned about insulation and wind protection than water protection so at this point, you should not be wearing low breath-ability shells such as Gore-Tex rain jackets. People typically will wear Gore-Tex shells to protect them from the wind only because of the versatility of wind and rain protection but the compromise if the fact that some water will be retained and not insulate as well. Laminates are rated by pressure. The higher the pressure rating, the less breathable the material is. Waders that are made with patented Gore-Tex aren’t very breathable at all because they have a high pressure rating against leakage. This means water cannot enter through the pores in the laminate but it also means very little water can escape from the inside as well. Some water does escape when you are not standing in the water due to water vapor transfer. Water vapor transfer is the only way a waterproof/breathable laminate can transfer moisture. If the outside air is cold enough, condensation occurs on the inside of the fabric, which can give the impression of leakage. Leakage only occurs at weak seams or in punctures or when the laminate is thin enough to allow some water to penetrate the laminate. Gore-Tex waders are probably the highest pressure tested laminate available and is estimated at 75 psi. Gore-Tex jackets are more like 40 psi. Some higher quality jackets with Gore-Tex XCR are still 40 psi but claims the breath-ability of a 25-psi laminate. This suggests a greater amount of breath-ability without the compromise in waterproof ness. In order to obtain the greatest amount of waterproof ness, all seams must be factory taped which is a process that can only be done by very special and expensive process and machinery. Contrary to popular belief, wading gear that is available from Simms is not the best gear available. Although they are the most technical company in the flyfishing industry, climbing clothing manufacturers have the best layering concepts available at his time. The best place to test technical clothing is right here in our backyard. Washington has a range greater than any other place in the world other than Alaska. Although I am expressing my opinion here, I believe ArcTeryx’ has the best Gore-Tex shells. A close second would be Patagonia and then third place would be Simms. I am sure Simms and ArcTeryx’ will have a contract in the near future considering Simms stress for the most technical wading gear available. I do believe that Simms manufactures the best waders though. At a very high cost though. Some pointers on layering techniques: What you wear on top, you should wear down below and all over if possible. This means if you wear a silk weight top, then you should wear a silk weight bottom. If you wear a 100-weight top, you should wear a 100-weight bottom. This only allows you to be able to remove your upper layer when you overheat so you will never have to remove your bottoms. Overheating is due to too much insulation trapping heat from your core. Also remember that you are usually standing in water from the waist down which means you should counter insulate. Wear more insulation where you need it, in the water. If you tend to get really cold on the coldest fishing days, wear down. Even if down gets wet by the end of the day, you can still throw it in a dryer when you get home and re-loft it for the next day. Also, remember to never wear cotton and try not to even wear wool if you want to keep warm. Marino wool is an exception. It has the best insulating value of any natural fiber. Here is the best layering system that I could come up with using the best and most technical manufacturers available: Base- Patagonia silk weight long sleeve crew and bottoms and socks Insulation- Polartec powerstretch 100 weight fleece top and bottoms by ArcTeryx’ Polartec 200 weight full zip bottoms (custom made)(use REI or other) Smartwool (simms) mountaineering socks Feathered Friends nylon 800 fill power down “Helios” vest Shells- Simms lightweight Gore-Tex Waders ArcTeryx’ Theta AR jacket in Forest Green ArcTeryx’ Cairn Pants (just nylon backpacking pants) Accessories- Simms fingerless gloves Outdoor Research Windstopper fleece hat with ear flaps Baseball cap Filson Packer Hat Outdoor Reasearch Crocodile Gaiters Simms Neoprene Gaiters I listed everything I use but I don’t necessary use all of them at once. I might exclude insulation layers or the lightweight nylon pants of I have to wear all of my bottom layers. I also typically reserve the down vest for when I get really cold or when I am moving really slow. If I get cold on the river with all of my layers on, I get out and start walking until I warm up again. I also bring a little stove and sierra cup and coffee press to make coffee on the riverside. I can fit the whole setup in my fanny pack with my fly boxes and additional layers. I hope this helps you guys out and feel free to ask questions and I will answer them the best I can. Also, please remember that I spared no expense and spent years trying to find the best layering system available. Most of my clothing crosses over for climbing as well. If you are on a budget, you can still obtain good layers for an inexpensive price.