Metalline is made up of multiple layers

The wound side:

Metalline's wound-contact layer is composed of a perforated viscose nonwoven material which is especially suitable for medical purposes. The individual fibres are coated with aluminium using a high-vacuum vaporization process. This creates a porous, non-adherent layer with a shiny, very smooth surface onto which wound exudate cannot adhere. As a result, Metalline does not adhere to wounds. This aluminium-coated Metalline layer is not itself absorbent and is not affected by water, blood or secretions.

The absorbent layer:

Because Metalline's aluminium-coated layer is highly porous the exudate diffuses into the absorbent layer, which very rapidly absorbs and retains blood and exudate. Draining blood is absorbed immediately and transported rapidly into the absorbent nonwoven layer by the capillary action of the Metalline pores. This has almost no wetting effect on Metalline's surface. The pores also ensure an unrestricted supply of air to the wound.

The top layer:

The top layer, which is made from a thin nonwoven material, covers the absorbent layer.