
The astral dimension is composed of astral matter and is aptly described as mind stuff. It is extremely sensitive to thought and can be moulded into any shape or form. These creations can be so perfect as to be indistinguishable from reality.
The best way to explain this, mind stuff is to draw a comparison between astral matter and unexposed, high-speed photographic film. When this film is exposed to light, focused by the camera lens, a perfect image of reality is instantly burnt into the film by the chemical reaction of the film to light.
When astral matter is exposed to thought, focused by the lens of the mind, a perfect image of reality is instantly formed out of astral mind stuff by the reaction of astral matter to thought. The complexity and durability of any creation in the astral dimension depends largely on the strength of the mind doing the creating.