Mid layer clothing for climbing

Here we look into the materials used for mid layer garments and why they are used: wind resistance, insulation, features, fit and function.

Mid layers provide the warmth of the layering system. The objective is to trap warm air close to the body without interrupting the movement of body moisture from the base layer to the outer layer.

Fleeces

Fleece material revolutionised the outdoor clothing market during the 1980s and 1990s. Nowadays Polartec, the best-known manufacturer of fleece fabric, make a wide variety: some are designed to look like knitwear on the outside, some is fluffy and works well to trap air when worn with a jacket over the top. Most outdoor brands make a variety of fleeces - a Polartec swingtag on a jacket is a good mark of quality.

Insulation  

If you 're going to be sitting on a belay for ages without moving, it is much harder to stay warm. Insulation is your number one friend. For those brutal Scottish winters when nothing can keep the water out a combination of 'pile and Pertex' has long been popular (Buffalo or DriClime). It is cheap and very effective at keeping you warm when you get wet. If you get hot easily or you are doing high activity it can be difficult to regulate your temperature (Buffalo shirts have extensive zips to deal with this) but it's certainly worth checking out if you're on a budget and need kitting out for winter.

Nowadays many people opt for synthetic insulation, and recently down sweaters (thin down jackets) have become increasingly popular as mid layers. Remember though - it's useless if it get wet! Hydrophobic Down is a new thing - this is an improvement on regular down but still not completely waterproof.

Features, fit and function
When buying a climbing mid-layer, look out for:

• Close fitting with good underarm lift
• Articulated elbows
• Shoulder and arm reinforcements
• A chest pocket big enough for your guide book
• A draw cord hem with a seamless waist
• Non absorbent cuffs (Powerstretch)

Above all, buy from a reputable manufacturer. Fleece bought from a trendy High Street fashion shop might look good in the store or in the pub but don't expect it to do anything more. There are a lot of cheap fabrics out there, don't let yourself get drawn in.