Wet finishing refers to the first time the wool fibres meets water after being woven. It’s often a more harsh process than subsequent washings. 

It’s necessary to agitate, steam and wash the wool in order to drive the process of fulling. During the fulling process, fibres migrate and compact. This results in stronger and more durable material.

It is not recommended to apply much more agitation and fulling as the material can break down, shrink and become otherwise less useful if the process is overdone.