Fleece - "technical wear" - traditional woolly jumpers - cotton... so much variety in the literal fabric of the clothing that we often overlook, yet we rely on in the outdoors!
We thought this a good topic, for winter and early spring, as we all ask the question so often: "what's right for the weather today?".
This question prompted an unexpectedly deep analysis of all the items in our own wardrobes!
We've done some research and will talk you through the pros and cons of each material, as we believe it's important to understand the detail (science) behind choices, even with clothing.
Basic Fabric
Raw fibre - All fabrics by definite are comprised of raw fibres, these may be thin and crinkly hollow tubes (like wool or acrylic), long, strong extruded man-made strings (like nylon and polyester), or loose, short "fluff" (like cotton).
Processed thread - Once fibres have been spun into thread and twisted with other threads, the style and functional behaviour of a material is starting to be determined. Thicker threads can be produced maybe for a stronger or thicker fabric style, or thinner threads to produce a smooth "close knit" material.
Weft/Weave - The performance of each clothing element varies depending on the construction of the fabric from prepared fibres. A tighter weave can prevent the pass-through of warmth or moisture, but also an looser, open weave can trap warm air in place. The combination of the properties of raw fibre and weave really matters.
Types of Fabric
Polyester. Holds warmth and is quick drying due to molecular structure, but thicker insulation requires bulky fabric layers. Able to be produced from recycled plastic, which is great. Polyester is also relatively hard-wearing, whilst allowing moisture to pass through. Good for a warm fleece layer, or thinner, wicking underlayer. Not at all warm when wet. Beware of polyester melting near open flames!
Wool, including Merino. Nature's wonder material, we should all use it more! The inherent fibre structure is a series of hollow tubes which help trap extra warm air. Moisture caught in the structure warms whilst adjacent to the body, and retains heat due to being held in the open spaces within the fibres; this means that wool absorbs moisture, rather than wicking it away, but remains warm when wet (and also heavy). The outer layers of wool fibre has naturally inflammable chemical components, as well as shedding light moisture. Wool (particularly Merino wool) also conveniently absorbs odours until washed.
Cotton. Lightweight and a core component of almost every wardrobe. Cotton in various forms has been a fabric of choice throughout history, as having a good balance in weight, protection from the weather and flexibility. Cotton is heavy when wet and retains little heat, so (as an example) denim is not good for damp weather. Cotton (and heavier canvas) have parallels from other plant-based fibres - particularly flax and hemp, which have good evidence of needing less resources to grow.
Acrylic. Man-made (extruded or spun plastic) sometimes with a hollow core, originally designed to replicate natural wool. It has good warmth and is quicker to dry than wool, but is not very breathable and holds moisture; so it's good for a cold dry day, but less good if the environment (or you) are damp. There is some controversy over the micro amounts of plastic shed by the material (apparently more-so than polyester), ultimately entering our immediate and wider environment.
Nylon. Highly durable and hard-wearing (even in thin layers) and flexible, Nylon originated as a synthetic replacement for silk and is mostly seen (in the outdoor community) as material in tents and sometimes waterproof clothing layering. Nylon is lightweight, can be treated with additional chemicals to boost its properties, and is quick drying. It is plastic-based, dangerous when melted and is not easily recycled, and thus carries controversies around broad use beyond specific purposes.
Lycra/elastane. A staple of modern exercising, Lycra is highly breathable and moisture wicking, whilst being light, flexible and comfortably close-fitting as clothing. The fabric has minimal heat retention properties and thus doesn't bring much use to cooler outdoor activities. We'd recommend lycra only for high activity in hot weather.
Leather. Flexible yet tough and hard-wearing, leather is generally heavier than man-made materials. It is often made to be waterproof during the tanning process, or with later applications, and will require maintenance to keep it supple and waterproof. Once wet, leather will take a long time to dry and will crack if rushed. Leather also offers some resistance to heat and wind. Good for boots (and maybe hats) if looked after.
Layer Up!
Many articles will reference the legendary "three layer" setup (wicking base-layer, insulating mid-layer, waterproof top-layer), or introduce variations with additional sub-layers. Our recommendation is simply to follow what seems appropriate and keep options available, either to add a layer from your rucksack, or take one off, depending on the climate and activity.
More important is to consider the material used on each clothing layer, as this is what determines the characteristic performance of each layer. An external layer should provide shielding from wind and rain, but potentially also allow moisture egress. An internal layer should keep you warm, in cold weather, or allow cooling in warm weather (noting that a thin wool layer can do both!).
This blog article really began out of personal observation of the many different fabrics and fibres used in clothing, with a view to being able to select the "best" for winter hiking conditions, in which weather may vary wildly between sun and rain, and be cooler on higher ground, also accounting for changes in body temperature whilst moving to when stopped. It is a topic which benefits from a little understanding of the fundamental material properties, and can certainly be analysed further.
Over any weekend TrexExplore outing, we are likely to encounter a wide range of temperatures, between the cool of the night and midday sun (irrespective of the time of year), but also considering the wind's effect and any potential precipitation. All weather changes require appropriate clothing in readiness! We hope to have provided a little enlightenment to help choose what clothing to wear or pack on your next adventures.
External references (no affiliation):
- https://sewport.com
- https://www.woolmark.com/fibre/
- https://www.thebmc.co.uk/mountain-clothing-for-climbing-and-walking