SECURE SHOPPING

WICKING                                                     

Under a microscope, this is what various fibres look  like :

Wicking? Or just dripping!

There is a lot of pseudo-science surrounding the subject of "wicking", so let's be clear about this.  A "wick" is a strip of fabric made of organic fibres such as cotton, linen or hemp, used in oil lamps.  Oil is sucked up by the porous fibres from the pool of oil.  When the synthetic manufacturers needed to describe the process by which their synthetic clothing dried, they obviously felt that the term "drip"  (for this is what it really does) was not suitable for their advertising campaigns, and so they came up with the idea of turning the noun "wick" into a new verb - "to wick".

                                                                 

The problem is that most oil-based synthetics cannot "wick" in any sense of the word as they are incapable of absorbing moisture, any more in fact that a plastic washing up bowl. They are non-porous.

Synthetics  do NOT “move” moisture from your skin to the outer surface of the fabric.  Instead moisture moves through synthetic clothing by virtue of the knit construction.  This ensures that the lines of knitting slope outwards, and gravity does the rest - dripping!

                                                                 

Merino, like all wools, absorbs moisture, but instead of being held close to the skin, the moisture is then shed it to its outer surface.  This is true "wicking".  No synthetic can do it - only attempt an approximation of it. Furthermore, merino will continue to keep you warm when wet as the fibres do not become waterlogged, whereas a wet synthetic fabric will feel cold.

                                                                

Keeping Dry & Comfortable

There is a commonly held belief that a wicking base layer will stop your clothing becoming damp and sweaty.   This is not necessarily true.  It depends on what you are wearing on top of your baselayer.

                                                                

When you work hard your body produces perspiration to help you keep cool.   If you are stark naked, this sweat normally evaporates from the surface of your skin.  If you are wearing a single layer of absorbent clothing, the sweat will be absorbed by this layer, and eventually evaporate into the atmosphere if it is warm enough.  When you stop working hard, or just slow down a bit, and start to cool down, the absorbent layer you are wearing will become cold and damp next to your skin.

A “wicking” garment is supposed to pass the perspiration through from your skin to the next clothing layer.   However it can only pass it from its own inner surface to its own outer surface.  Each succeeding layer must do it's own job of passing on the perspiration to the next layer until it eventually gets to the outer surface and is passed into the atmosphere.   If one of these intermediate layers is absorbent it will absorb the perspiration as well as passing it on - but only "if".   As we said before, synthetic fibres do not absorb moisture.  They "drip". Their interlock construction allows moisture to trickle down through the gaps.

You can therefore have the situation of wearing high performance wicking underwear giving you a dry comfortable skin but your cotton or synthetic midlayer is very damp under your breathable jacket, making you feel cold - and possibly giving you wet feet!

                                                                 

For maximum performance wicking underwear requires a middle layer which will wick at a similar rate and an outer layer capable of passing the perspiration rapidly to the atmosphere.   Because of merino's ability to both absorb and shed moisture, and because of its ability to keep you warm even when wet,  it makes an ideal base layer and mid layer under any outer layer.                                                                 

Plant-based Fibres and Fabrics

There’s saying amongst those who spend time in the outdoors in all weathers - “cotton kills”! There’s good reason for this. Clothes keep you warm by trapping the warm air generated by your own body close to your skin.  All fabrics will do this. It’s what happens when they get wet is what makes all the difference.

When undertaking any exercise,  the body sweats.  Cotton, like all cellulose-based fibres, will absorb that moisture like a sponge,  the air pockets in the core of the fibre become waterlogged, and can no longer trap air.  If the air around you is colder than your body temperature and your cotton clothing is saturated, you have lost vital insulation. This can lead to hypothermia and can happen in temperatures will above freezing, because of the wind-chill factor.

There are other cellulose-based fabrics on the market now, bamboo being one, which can absorb moisture at a terrific rate.  The problem is they not only absorb far too much moisture, they hang on to it, creating a cold wet garment that can add to the dangers of hypothermia for the wearer.  For use in hot dry weather, these fabrics may be fine, but they are not suitable for all-round, all-weather, garments, and particularly not for cold wet conditions.

Bamboo fabric is in fact old fashioned "Rayon".  It wasn't good for outdoor gear back in the day and in our opinon it isn't now.  It's "environmental" credentials are doubtful as are it's claims to be "antimicrobial".            

Silk is equally poor as a fibre for outdoor clothing, as it’s also vey absorbent and loses its insulating properties when wet.    The only reason it was added to wool for undergarments was to reduce the itch factor or coarse wools.                                                

                                                                              

Layering Design - style or function? Multi-climate merino

Technical Characteristics of Merino

Judging quality magnification images of merino fabric Electron Microscope images of merino fibre

Processing Wool

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