Cellulose microfibres, which are a natural material as they are wood dust, are used to give a consistency to the resin increasing the resistance, they help a lot to increase the adhesions. They can be added to other additives such as micro-fibres to create a range of different fillers depending on the requirement.
Very fine hollow glass microspheres, used to give body without increasing the weight too much, in creasing and for filling large surface imperfections. When added to other additives, it improves spatulability and the grain of the putties obtained in this way. It is compatible with any type of resin