While it is easy to ask people to cover their face, finding a fabric or textile which does not have an unpleasant smell is a major challenge
Smell is important for a face covering, since the face covering is close to the nose
Often the fabric may not have a unpleasant smell initially.
Yet after it is soaked in sweat, most fabrics have a very unpleasant smell.
The smell is worse if some sunscreen is used on the face
In some cases, the smell is so unpleasant, that the person may feel like vomitting