I'd like to ask what is the "best" synthetic fiber fill according to your experience and knowledge and understanding of the technologies. Especially when comparing the two that are considered probably the best: Wiggy's Lamilite and Primaloft. This is a frequently asked type of question and I thought it would deserve a dedicated thread on the equipped.org forum. Why would Lamilite (Wiggy's) be superior to others?

On another forum I've read somebody comparing Wiggy's Lamilite with Primaloft and he said it's like the difference between paper towels and toilet paper (but he sells Wiggy's bags at his store though). I got myself a North Face Plasma Thermal jacket which is isolated with Primaloft and think it's pretty warm for the weight (and the shell and high collar acts like a medieval armor against strong freezing and breathtaking gusts of wind in the neck).

Also what about hybrids of fiber fills and natural down such as the MEC Hybrid? is it a good idea?

I think I need a primer on fiber fills too.

Thank you.
Frankie boy

Primaloft is the closest man made fiber to goose down. It is a better choice for cold wet conditions than down. And it's no slouch beween +10 and about -20 C. Below that you need wool and down.

Primaloft and Qualofil seem to be the two most efficient synthetic fills on the market. Both are based on hollow core semi rigid drawn fibers, which seem to be about as good as you can get. Synthetics work better when wet, much better in fact, than down will. Wool is considerably heavier than down or synthetic for the same insulation level, but it had other advantages.

I have been a HUGE fan of synthetics for years. Living in new england, stuff can get soggy sometimes. I currently own two sleeping bags that I use regularly. One is a down 20* bag, which works fine almost all year round. The other is a polarguard 3d bag from EMS, rated to 35*. As compressible as down is, the synthetic packs smaller.
Some disadvantages of synthetics are that it breaks down easier, MAY not be as compressible as down for the same rating. However, they are fast catching up. Disadvantages of down are if they get wet, they are useless (although, sleeping in any wet bag isnt fun). They require a little more care, but generally last longer than synthetics.
With all of the advancements in synthetics, given the choice, I would go with man-made materials. You get what you pay for though; for a good bag, expect to pay a pretty penny. Go through discount outdoor stores for good deals too. campmor, sierra trading post, etc, all offer decent deals on bags. Good luck!

I actually prefer natural materials; wool, leather etc. for several reasons. But for ultimate insulation I depend on lamilite. Wiggys site is an excellent, if long primer on the subject.

I have to agree, nothing wears like good leather and wool.

Raining and 35 degrees C here in Singapore today. Not much chance of hypothermia, but miserable just the same.

I have never been warm in a synthetic bag. Once I went all out and bough the most expensive, lowest rating, man-made fill bag at REI. It was supposedly rated to something like -40F, don't remember. The point is, I froze my *ss off in a trailer with no heat at only about -15F. And I was wearing all the clothes I had with me!
Ever since then I only carry down bags. If a rain is expected, I simply pack it in a large bag and stuff it deep inside my backpack. Never had any problems this way.

I agree, Chris. When the chips are down (no pun!) give me my Filson coat, pants and hat - and my Woods Arctic down rectangular with liner - COMFY! Also, give me a pickup to haul it all around! When the chips are almost down - and I'm on foot - I'll take Lamilite. It is amazing stuff. Light, compressible, and bounces back. In my BOB I also carry a polarguard, well-made bag by Sierra Designs. Also good and light.