I have all but given up on synthetic base layers for use during multi-day outdoor activities simply because of the stink factor. Not wanting to rid my pack of them completely, I have found a new and improved purpose for my poor polyester outcasts as warm and comfy camp shirts. There is nothing better than rolling into camp all sweaty, setting up your tent, then changing into a dry, cozy top in which to lounge around camp and sleep.
If you are headed out on a backpacking trip, I highly recommend bringing an extra shirt (and socks) that you use just for camp. Your collection of synthetic base layers should fill this role perfectly, as you shouldn't sweat much while simply cooking dinner and sleeping, cutting down on the risk of odor accumulation.
Although I love my merino wool base layers for use during daily activities, I am not a huge fan of sleeping in them at night. I find rolling around in wool irritates my skin. The brushed interior of most fleece base layers is more soothing during the night.
Some of my favorite synthetic base layers that have regularly found their way into my pack the past year are as follows:
Because of the warmth, I originally tried the Sherpa Priya as an ice climbing base layer, but I could only wear it for one day out before having to throw it in the wash. The pullover is now my go to camp shirt and recently kept me cozy through the chilly nights on my winter backpacking trip to Yosemite.
Made from Polartec Thermal Pro fabric, the Priya offers plenty of warmth without a ton of weight (7.8 oz.) Thermal Pro fabric is moisture wicking and quick to dry in case you need to give the top a quick wash during an extended trip in the backcountry.
Gathered stitching at the bust and contrasting colors add an element of style to the normally boring base layer. I have been wearing the Sherpa Priya around town as a regular top as well.
The North Face TKA 100 Masonic top is made from the super soft and textured Classic Polartec 100 micro fleece fabric. Offering lightweight warmth and breathability, the stylish fleece is super comfortable against the skin and will pack down small. Much like the Priya, the Masonic will dry quickly if it happens to get wet or you need to do some outdoor laundry.
Sadly, it looks like Cloudveil may have discontinued the Run Don't Walk base layer line but you can find plenty of equivalent options, such as the Mountain Hardwear Power Stretch Hooded Top (MSRP $105), made from the same Polartec Power Stretch fabric. This body hugging, 4-way stretch fabric traps in warmth, with a soft inner layer that is comfortable against the skin. The smooth fabric outer layer is even good at blocking some wind, nice for when you are sitting around camp.