Saying the Dry Mesh baselayer is reminiscent of an old school string vest doesn't do it justice. But it kind of does. Altura Dry, an open weave 'tubular knit' fabric, is built to remove moisture from the skin effectively and this is combined with a 'body mapped' close fit to maximise this effect. The theory is that it increases the surface area for sweat to evaporate from, increasing the rate of evaporation and therefore the cooling effect from that. Wind can pass straight through, so no air is trapped that would otherwise insulate.
We find that using it under a thin and air-permeable outer layer such as a standard road cycling shirt it does exactly as we would like - wicks sweat to increase the cooling effect. At no point, no matter how warm it gets, have we wished we could stop and remove it.
When the weather cools we find it actually helps too. Coming out of a cafe into a cool evening, for example, we have found it to be a great help at retaining heat. Just pulling a windproof layer over the top traps air in that chunky mesh, turning the tables and keeping heat in when needed, so it is more than just an aid to cooler riding. Throw the windproof off after a few miles and the cooling effect steps straight back in, evaporating any built up sweat before the big effort starts to overheat once again.
At £40 it may seem like a lot of cash for a thin shirt, but this is actually a very versatile bit of kit that can help when too hot, but step up its game with the help of a windproof outer layer when you need to retain a little heat. Make no mistake, this is no string vest.