Seems to me it makes more sense in theory for layering purpose to use 2 pairs vs a thick single baselayer.
A couple of questions:should you use a mid and a lightweight pair or 2 lightweights?Second, if you normally wear a medium would your 2nd pair be a medium or large so it aint too tight?Medium fits me snug-tight whereas large is baggy on me so if my 2nd layer was baggy in areas i guess this would defeat the purpose?

Is this for active use or in camp/sleeping?

If active, I'll let the snow shoeing, skiing crowd offer input. If the latter, then why not add a light puffy insulating layer, a-la the Montbell UL down inners?

If price is the main sticking point, then yes, get the 2nd layer cut a little larger than the inner layer. The puffy will be a lot warmer too.

Better to use 1 lightweight base layer

Base layers are heavy for how much warmth they provide

Better to use down or synthetic insulation

If it's really cold during the day, maybe a fleece mid layer

I am talking about for winter activity like snowshoeing on really cold days.
And i am talking about baselayer bottoms for legs.

Jerry's right about fleece as a good option. I'd rather do one fleece layer than two light base layers.

that being said, a silk-weight layer or comparable under an another base layer isn't going to be much of an issue. What are you wearing for pants, and how cold will it be when you are snow shoeing? I wear woven softshell pants and couldn’t imagine wearing a heavy base layer or a mid/light weight layer combination and not be too warm. I’d much rather be cool when active than hot. As with the others above in winter with a light weight base and softshell pants I layer insulation over the top for real warmth when needed. I am not taking my pants off (maybe for multiple days on an overnight trip) to adjust my base layer.

Edited by RICKO on 12/31/2012 14:03:44 MST.

It depends on how you expect that the weather will fluctuate.

If the temperature is fluctuating a lot, then you need the maximum versatility in layers. That probably means thin layers with a thicker layer over. That way, you can wear zero, one, or two thin layers.

For one high-altitude expedition, we knew that it was going to be pretty consistently cold, so I wore medium weight fleece tights with thick wool trousers over that. That went for a couple of weeks, and for most days I had goretex rain/wind pants on over that.

--B.G.--

I wear regular rugged or regular nylon zip-off hiking pants for winter snowshoeing in the sierra.Temps are usually in the 30-40s but i want to be prepared for colder temps.

Thanks for answers so far.What type/brand of fleece pants are you guys talking about?

I'm a big fan of RAB vapor-rise pants for winter. Very warm but breathable pants with a micro-fleece liner. My favorite winter hiking pant.

Running tights and gym shorts and a pair of wind pants for if it gets breezy. If tights aren't your thing, acme or mistral soft shell pants from REI or the functional equivalent.

Edited by RICKO on 12/31/2012 20:37:55 MST.

I use the Golite Windriver Softshell pants for snowshoeing. Was out two days ago in 15 degree weather with nothing on underneath and felt perfect.