Down vs. Synthetic Insulation

This is a common topic in the skiing and backpacking industry but not so much for hunters. With today’s technology applied to insulation, both options are lightweight and will keep us much warmer than just piling on layer upon layer of fleece and wool. Hopefully you’re not wearing any cotton while hunting the west. Remember: COTTON KILLS! Why do I say that? Cotton does not dry quickly nor does it insulate, and it is heavy. It might suffice for a two hour glassing session close to the truck, but not in the backcountry when you’re depending on your gear for survival.
On a recent hunt in southern Colorado, we spent hours in the early morning glassing for Mule deer bucks. Usually we would climb a hill/mountain to get a good vantage point and then sit and glass. The hike in the darkness was steep and carrying all those optics and tripods resulted in a nice sweat. Getting soaked by sweat and then sitting for hours is a good way to get a chill. To beat this problem, I started cold, leaving the truck wearing just one merino wool base layer. After five minutes, I warmed up and made it comfortably to the top without overheating and having to remove any layers. One problem I have yet to decipher is that wearing a pack almost always results in a sweaty back. There is no way to get enough airflow between you and the pack to completely stay dry. At this time you decide what to put on next to endure the glassing session. You could pull out 2 or 3 or even four more layers from your pack and start layering. This would work, but carrying all those layers adds weight. One down jacket, weighing less than a pound, and packs just a bit larger than a 1qt. bottle; this is the answer. Down, being a lightweight, breathable material, will let my soaked back dry out, and keep me snug all the way. When it’s time to move locations or give chase to that big buck, I simply stuff my jacket in my pack and I’m off. I use a Mountain Hardwear Phantom down jacket when I need reliable warmth in a small, lightweight package in a cold and dry climate.
In a dry environment down does great. However, down does not do well in a moist climate, but synthetic does. Let me explain. When down gets wet, the down clusters (feathers) get matted together and do not trap air between them. This is called “losing your loft”. The greater the loft, the more heat is trapped, resulting in you staying warmer. No loft=no warmth. Synthetic insulation is hydrophobic, meaning water slides right off of it. When my Mont Bell Eldo jacket gets wet, I can literally shake 90% of the moisture out of it and then let it hang dry. Synthetic insulation maintains its loft when wet, trapping air and heat even when soaked.
Down is lighter with a higher level of loft, but fails if it gets wet. Synthetic insulation is heavier, but works well when wet.
Both insulations have their time and place. For most of my backcountry bow hunts in September, when our temps are still mild, my synthetic Eldo jacket gets the job done. It would be a cold night out with that as my only insulation, but I would survive. When the snow starts to fly and temps are routinely in the single digits in the mornings my Phantom down jacket is always with me. In a worst case scenario, it’s like having half of a sleeping bag, and that goes a long way during a cold night out. Whichever insulation you choose, always carry a lightweight Gore-tex jacket as your first line of defense. This crucial layer stops wind, rain, snow and protects your insulating layer from getting soaked. By choosing the proper insulation and a waterproof jacket, you’ll carry less gear and be able to withstand just about anything Mother Nature can throw at us, leaving you ready to go when the weather clears.