How to know the difference between products warmth eg. pat wool 2 vs. smartwool midweight vs. icebreaker 260

Basically, you'd probably do well to break this down in two ways:

1. Compare different materials to one another based on their clo values. If you do a search in these forums you should find a lot of information along these lines.

2. For comparisons within material type (e.g. comparing merino wool to merino wool) you'll want to focus on the density of the fabric, usually measured in grams per square meter. The more dense the fabric, the warmer it will be.

The Icebreaker line is a good example of this: The numbers in their Bodyfit line represent the density of the wool. Bodyfit 150 has 150 g/m^2, 200 has 200 g/m^2, 260 has 260 g/m^2.

Does that make sense?

By the way, if you want a tech-ier response their are others on this board that are better suited to give it to you, but I think this my answer might work as a sort of primer on the basics.

Edit: Here's a link to Patagonia's info on their capilene and wool products: http://www.patagonia.com/web/us/product/shop/pbl_shop_landing.jsp?OPTION=PBL_LANDING

That might be helpful for you as well.

Because there are so many variables, the best way you'll find out how your clothes perform is to so out and see for yourself.

I enjoy reading the technical discussions and understand the concepts, but when I tried to transfer the info to reality, I either took too much or not enough. At first, I'd take an extra layer, but find I did not need it. So next time, I'd leave it and then later think about how nice it'd have been to have it as I shivered.

Now what I've settled on for each trip is to estimate the coldest temperature I'll encounter and take a combo of clothes/layers that will handle it. I try to make each layer as light and thin as possible. For example, a wool 2 under a wind shirt works well for me when I can switch the wool 2 with a cap 1. Get warm, take off the wind shirt.

Of course, this all sounds so simple, but it took me a while to figure out what works for me. I'm not sure if my early problems were from information overload or my lack of understanding.

Pat. Wool 2 is 148 g/m2 or maybe 155 g/m2 so that is certainly the thinnest of the shirts you have listed. I'm not sure on the smartwool, but I'd imagine it's slightly less warm than the 260. I find the smartwool a little bit itchier than the patagonia or the icebreaker.

Are any of these wool companies making the items in the USA? (Ibex, I think, does.) Or is this mostly a China outsourcing for Smartwool, Pata, and Icebreaker?