UNDERSUIT

Staying dry is as important as staying warm: it's best to use professional drysuit undergarments by Fabrizio Pirrello.

Important information to understand what you're buying.

The drysuit undergarments found on the market do not indicate a mandatory information that It is the thermal protection coefficient offered.

This coefficient is expressed in tog or in clo and not in terms of water temperature for which it is recommended.

Thermal protection is not given by the weight per square meter!

Thermal protection cannot be indicated by reference to water temperature: cold tolerance is very subjective.

A scale that expresses the thermal protection coefficient is something objective: it is a number we can compare to understand which drysuit undersuit is warmer than another.

Ask yourself why almost no one indicates the thermal protection coefficient and instead refers to material weights and similar.
Simple: it's not worth explicitly declaring how much it protects their product.
Drysuit undergarments can be designed as a one-piece with a double-slider front zipper or as a two-piece jacket and pants.
The drysuit undergarment is always a garment constructed by combining multiple layers, each of which serves a specific purpose.
The layer in contact with the body is always made of hypoallergenic fleece and has the specific task of absorbing moisture from body perspiration to keep the diver's skin dry. The immediately following layer  Its job is to transport that moisture to the outside and trap some air between the fibers to insulate the body from the cold coming from the outside environment. The outermost layer, on the other hand, must prevent sweat from flowing back and at the same time must quickly evaporate moisture without cooling the body.
The outer layer is normally what determines the elasticity and smoothness of the garment. If the exterior is made of nylon, the elasticity of the undersuit is necessarily limited (for this reason, some manufacturers insert stretch panels to aid mobility), even if it improves sturdiness. Nylon, microfiber, Pertex, and external coatings make the undersuit slippery on the inside surface of the drysuit, making it easier to don. The mid-layer fiber can be THINSULATE, METALUX, or POLARTEC. These are all synthetic fibers whose purpose is to trap a film of air warmed by body heat, using it as an insulating barrier against external temperatures that are lower than the body's own. METALUX also has the ability to reflect part of the diver's body heat back towards the diver, increasing thermal protection.
The THINSULATE undersuit should be periodically dry cleaned in a laundry to preserve all its insulating properties. The METALUX or POLARTEC undersuit is suitable for home washing, by hand and in water at temperatures below 30°C.
But why does the undersuit get dirty even when we are careful? One of the functions of the undersuit is to remove moisture from the skin, so it becomes greasy with body sweat. That greasy film, mixing with the dust that is normally found in the air, tends to block the pores of the membranes, thus limiting the migration of sweat from the body to the outside and therefore reducing the breathability of the garment.
Metalux® is a unique undersuit material: insulating and reflecting the heat emitted by the diver's body back towards the body. It enjoys an enviable reputation for being one of the lightest and most insulating materials available. It is designed to reduce the movement of air trapped in the fibers and reflect thermal radiation.

Metalux® maintains its impressive insulating qualities when wet or compressed, and thanks to its quilted construction, it maintains thermal efficiency throughout the garment. The material is lined with fleece for maximum comfort. It is also resistant to bacteria and fungi and can withstand repeated washing while maintaining its properties intact.