Silk as a baselayer?

Silk as far as textile fabrics go, is pretty warm for the weight. It has a combo of interesting properties that combine to make it so.

1. the fibers often are very fine–finer fibers trap more air than coarser/larger fibers.

2. the fibers are triangular shaped. A research study on fiber insulation and properties in garment form found that triangular shaped fibers trapped/stilled more air than round fibers.

3. It's made out of protein, and so it's thermally fairly non conductive, like wool and other protein based fibers, though it's different in some ways. So like wool, polyester, and polypropylene it has some "warmth" when wet properties relatively speaking–especially as compared to the more conductive materials like cotton, linen, rayon, etc and even nylon to a lesser extent.

But it has some down sides too. I've been looking for polyester-silk or silk-polyester blends to try out as baselayers. For some reason, extremely hard to find. Dri Release makes a Dri Release silk version, but that only has 12% silk. I'm looking for a higher percentage of silk to decrease odor and increase insulation. Would like to try around half and half, or 40% silk to 60% polyester or somewhere in between the former two.

It seems to me that a blend between silk and polyester would make a great baselayer. While it won't have the super excellent odor inhibiting properties of high wool to synthetic blends, it will be much more durable and possibly even a bit warmer, as well as dry a bit faster. Wool absorbs more moisture than does silk.

I've tried pure silk, its ok for sleeping and rest, but not so good for exertion. Some say silk "smells". I suspect that they tried the DWR treated silks, which of course will tend to smell more–the DWR treatment temporarily turns it more like into synthetic for that property. Untreated silk has ok to decent odor inhibiting properties. Better than cotton, much better than untreated synthetics (especially polypropylene and polyester), but not as good as wool or linen/hemp.

I'm a bit of fabric textile nerd…

Theoretically speaking, one could design polyester to be warmer than silk per weight, because the fiber shape and size can be so manipulated, and being a stronger and more durable material also has it's advantages.

For example, Polartec Power Dry High Efficiency material, such as Patagonia uses for their Capilene 4 stuff, well you would be hard pressed to get more warmth per weight if you combine that with a wind resistant shell of some kind, compared to most any other type garment. Sure, it will be heavier than a thin silk, but it will be both a lot warmer and more comfortable over a wider range of conditions.

The odor with polyester is an issue for some, but fabrics like the above, are increasingly being made with Polygiene treatments which do a decent to good job of helping that issue. However, such fabrics and garments tend to be on the expensive side.

If you want to treat a polyester shirt with silver for cheap, check out my MYOG thread about it.

I have taken a liking to Patagonia silk weight Capaline 1 base layers. They are pretty light..they dry super fast..they are comfortable. .not too expensive either. They kept me warm this past winter in new york when layered properly and I will see how they work in warmer weather this season when I get out. Not sure if this is what you were looking for..just my 2 cents..