Varnish is a type of coating that is used to protect and enhance the appearance of wood, metal, and other surfaces. The ingredients used to make varnish include rosins, lacs, resins, and elemis. Rosins are a type of solidified resin obtained from coniferous trees, while lacs are a type of resin secreted by certain insects. Resins are a type of natural or synthetic polymer that can be used as a protective coating, and elemis is a type of plant-based oil used in varnish recipes.