Hollow Glass Microspheres is a new filler material industrialised in recent years. It is made from borosilicate and shaped in hollow microsphere with grain size 10-250μm and wall thickness 1-2μm. It has light weight, low heat and sound conductivity, high strength, and fine chemical stability. It is also lipophilic, hydrophobic and very easily dispersed in organic materials such as resin.
It is widely used in aviation and space industry, bullet trains, luxurious yachts, heat insulating dopes, bowling balls. It can also be used in composite materials such as FRP (fibre reinforced plastics), man-made marble and agate.

Cenospheres is an alternative for Hollow Glass Microspheres.