So which base layer is going to suit my needs best?
Broadly speaking baselayers fall into two distinct groups: Synthetic Fibres, or Natural Fibres.
Produced from petrochemical sourced yarns, such as polyester, polypropelene and polyimide.
For - In general they tend to wick moisture away from the body quicker than natural fibres, and dry quickly.
Against - Without additional treatment they can tend to suffer from odour relatively quickly - however, treatments such as silver ions can help reduce this problem.
At Action Outdoors we offer synthetic baselayers from Arc'Teryx, Mountain Equipment, Paramo, Outdoor Research and Tilley.
The yarns in this group are derived from natural sources, with Merino Wool being the main fibre used but Silk is still a viable alternative.
For - Merino in particular is more resistant to odour, so may be more suitable on longer trips with limited washing facilities.
Against - Merino tends not to wick as well as synthetics, but it does have a bigger capacity to absorb moisture. It also tends to dry more slowly, but does retain its insulating properties better when wet than synthetics.
We use Smartwool for our Merino baselayers and Silkbody for our silk based products.