Montane have blended Primaloft with merino wool in their latest base layers and imaginatively called them 'Primino'.
Mixing synthetic and merino to try to get the best out of both seems a no-brainer, synthetic is usually highly breathable, quick drying and lightweight whereas merino is warmer and naturally anti-bacterial so do you get the best of both worlds with the Primino's?
Well, they seem highly breathable in use and wick moisture away with aplomb. The 140g weight and merino wool content make them warm enough for use as part of a layering system in cold mountain climates while still feeling fairly light and easy-going to wear. Comfort is helped along by the soft elasticated waist and flatlocked seams which help to reduce irritation.
You don't get any noticeable shrinkage on a 40 degree wash and they predictably dry quicker than a 100% wool fabric but not as quickly as a 100% polyester fabric.
The fit isn't as tight as some base-layers we've tested which I personally prefer and the reduction in merino means it's less itchy against sensitive celtic skin than a full-on sheep based garment.
The overall impression of the Primino baselayers is pretty good and they certainly go some way towards addressing the pitfalls of the two leading technical materials, they also do it at a reasonable price, retailing at £50 for the long johns and £60 for the zip neck top.
For multi-day, multi-activity use the Montane Primino baselayers are a pretty safe bet.