Various sealers can be applied over clay and lime plasters to enhance or protect them in vulnerable areas. The appropriate sealer will depend on the level of protection required and the desired appearance. 

Wax is the most natural looking sealer and the most commonly used on polished lime plasters. They give added sheen and dirt rejection. 

Repel retains the natural matt finish of most plasters and renders and gives water repellency. It is more commonly used on clay plasters, as clay is naturally very water absorbent.

Black Soap is a traditional sealer for lime plaster finishes that has a soft matt lustre and when applied correctly will give extra water repellency than wax. 

Vetro is a more heavy duty sealer for areas such as bathrooms that need to be frequently cleaned.

Oro and Gioia are decorative glazes that are applied over plasters.