Binders and fixers are natural glues or synthetic resins whose function is to bind together fillers or aggregates and to stick them together on different substrates according to their compatibility. There are different types of binders and fixers. Natural binders and fixers such as casein and synthetic binders and fixers such as acrylic or vinyl binders. Natural limes are part of natural binders such as air lime paste or powder and natural hydraulic lime (nhl3.5) or Roman hydraulic lime. They are not fixers because they do not add to mixtures. they are necessarily the main binder of the mixtures.