**3.1. Role and function**

In addition to compression layer, the role of padding is also critical in the successful treatment of chronic venous disorders. A suitable thickness of padding (~1–2.5 cm) is used between the bandage and skin layer for uniform pressure distribution [5, 29]. Padding is wrapped under‐ neath the compression bandage and left over the wounded area for long period of time. In order to distribute pressure evenly around the limb, it is essential that high pressures created at the tibia and fibula regions are absorbed by the padding material. The normal pressure applied by the compression bandage gets absorbed and distributed within the structure of padding bandage. Some amount of pressure is dissipated in the structure, and the rest is transmitted through the thickness of the padding bandage to exert final absolute pressure on the patient's leg. Padding can also be used to reshape legs which are not narrower at the ankle than the calf. It helps to reshape the limb more like a cone-shape so that the pressure gradient can be achieved with more pressure at the ankle and less at the calf.

In addition to pressure management by padding, the other concern is to maintain good thermophysiological comfort and to ensure better compliance for the patient during the course of compression treatment [30]. The thermo-physiological comfort concerns the heat and moisture transmission characteristics through clothing, that is, transmission of heat, air and moisture (liquid and vapour) [31, 32]. Multi-layer compression systems, such as 4-layer bandaging, are used for extended periods of time with minimum dressing change. This may cause overheating of the underlying tissues and, perhaps, excessive sweat production due to poor air or moisture exchange between the body and the surrounding [33]. Clearly, the removal of excess fluid or exudates is extremely important to avoid irritation and ensure comfort to the patients. Overhydration or even maceration of the underlying tissues is likely to happen if the body fluids are not continuously removed from the affected region. Improper management of excessive wound exudates or other body fluids may delay healing and lead to other complications. The padding is used underneath the bandage and therefore is in direct contact with the skin. The interaction of fluids with the padding is therefore critical, as this determines the ability of padding to spread the liquid to a wider area and therefore helps in faster evaporation and prevention of excess moisture build-up. This will also provide better comfort to the patient. Furthermore, the surplus heat produced due to muscular activity should be discharged into the surrounding to facilitate wound healing. Several properties of padding including air permeability, moisture and thermal transmission, wicking, etc., are important here to finally ensure better thermo-physiological comfort of the compression product.

**Figure 2.** Important physical and physiological factors affecting padding comfort

Other comfort for padding includes the sensorial or tactile comfort which is related to the mechanical contact of the fabric with skin, that is, how a fabric or garment feels when it is worn next to the skin [31]. These are fabric handle or feel, softness, fullness, warm–cool touch, static charge generation, flexing, pricking, itching, etc. The physiological comfort, such as fitting, which is related to aesthetic properties of the fabric, that is, drape, lustre, colour, crease, pilling, staining, etc., are not our concern for the padding application. Figure 2 lists the important physical and physiological factors affecting padding comfort. Among all comfort characteris‐ tics, the most important factor is the movement of heat and moisture (liquid and vapour) through padding to maintain the thermal equilibrium between human body and the environ‐ ment.
