Terramar Thermasilk – cold?

I too found silk base layers to be of no use for warmth. To keep things clean only I think.

Silk will hold a LOT of perspiration and, IMHO, is for sedentary situations.

For sleeping it's up to you but I like thin polyester long johns for spring and fall or summer above 7,000 ft. Plus they can be used as a base layer if the temps stay low.

We use silk for SB liners to keep the down clean, but not for wearing as clothing in bed. Yes, can be a bit cool.
(I should add: we also use UL synthetics for liners.)

Cheers

I find the same. I think they may be useful for a base layer during strenuous activity where you just want to transport moisture but even then I tend be too lazy to pull them out of the pack so they mostly stay at home.

I use a midweight synthetic or wool for sleeping. I guess if I hiked in hot, warm weather the silk layers might find some use.

Yeah, they don't offer much warmth though I haven't experienced the cold draft feeling described here. I mostly use them just to keep my dirty sweaty skin from soiling my bag. They're only 2oz so I don't expect much from them.

Ryan

I used Thermasilk for sleeping on my last trip. I aggree that they tend to feel pretty cold if exposed to cool air. Since it was warm on the trip, I was fine. I guess for colder nights, I would just wear my puffy jacket over the longsleeve and consider bringing wool longjohns or use rain or hiking pants over the bottoms.
However, no doubt that a wool longsleeve is more efficient, especially if you uncover your arms/upper body for venting. I guess just as always, weight savings comes at a price.

I am conflicted. Last year, I hiked the JMT and wore thermasilk for the first time and used a 20 degree duck down quilt for the first time. I found that I was sweating early in the evening and would need to strip down to naked. Then as the night wore on, I would need to add the silks and then later the hiking pants and shirts and some times the xlight down jacket to stay warm enough until daybreak.

Any suggestions are greatly welcome.

It has more to do with your body and its thermo-regulation than it does the garments you wear.

Eat and drink more before bed. For me as I get older I notice less ability to stay warm at night so you have to play the same game as when moving. Take layers on/off based upon need. Just life.

I'm with Eric. I managed to find a pair of silk longjohns in a thrift store for $2 (I know, but I couldn't pass on the deal). They are light and plan on using them in SoCal summer months for keeping the quilt clean. But at 3 oz. heavier, I still like polypros for the pants when it come to sleeping warmth. I have a Merino wool long sleeve 1/4 zip shirt that I usually bring for a sleeping/extra insulation layer as it breathes much better if pressed into service for hiking, but the Polypros of similar weight are warmer.

I have the same ones. My experience was they felt colder in bed than just wearing my underwear but I suspect that it's just a feeling rather than reality.

I used thermasilk bottoms and a lightweight wool top on my recent trip to San Jacinto. It was 41 one night and 48 the next. I was warm with a 20 Phoenix underquilt and 30 EE Revelation top quilt (in a hammock). I could have used wool bottoms the first night. I need to wear something to keep my hammock and quilt clean, and its easy to vent quilts without shedding layers.

I think the silk bottoms are great above 50 since they weigh so little. Synthetics seen to create a static storm with my polyester hammock, so I prefer natural fabrics. I would think they would add warmth under wind it rain pants as well if needed early morning of if tennis drop.

silk is great for adding some air flow up against your body but not insulating at all unless tightly knit. I use loose silk under wool for reasons stated above, I find it helps to keep my wool drying faster on my body which makes it seem warmer (live in pnw with lots of rain). Also some high end silks are just great for feeling naked when fully clothed.
Anything is better than plastic imo, but plastic thermals work better than silk ever will.

Just a short follow-up: I tried these at home again after washing them post-trip (I hadn't washed them before the first time I used them). The flash-chill effect I described earlier isn't nearly as noticeable, though it is still there to some degree. They also don't feel as cold to the hand when handling them up. Perhaps they had some coating left over from manufacture (a lot of dye came out when washing), or maybe washing roughs up the fibers a bit. Still, I don't know if I'll try them on a trip again.

Silk fibers are in reality a decent insulator because the fibers tend to be rather fine (small diameter), have a triangular shape to them (the combo of these help to still air), and being protein based is fairly non conductive (conductivity only seems to be important when the fabric is directly on the skin and/or a lot of moisture is involved).

But any super thin and very breathable fabric is going to feel cool on the skin, especially if there is any noticeable moisture involved.

For silk to feel warmer, it needs to be more tightly woven and thicker, but then it will hold a lot of moisture potentially, though not as much as wool.

Some silk baselayers (like REI's) are treated with a DWR nowadays, to make them absorb less initial moisture. This can make them stinkier. Not sure if it would affect sensation of cool or warm on skin though.

I'm interested in trying polyester silk blends for a active baselayer–something like 70 to 65% polyester to something like 30 to 35% silk. Why, to cut down some on odor (after treatments wash out, which most invariably will), to add some sustainability, to increase wicking, and to increase skin comfort. I don't think all silk is particularly good for active baselayer though.