The concentration of the mixture can vary depending on application, but is typically 30% glass fibers, 25% filler, and 45% resin, styrene, and initiator.
[2] The material is provided in bulk or in logs approximately 4" in diameter.
The viscosity of BMC dictates how effectively it can fill a mold.
The viscosity constrains the amount of each component that can be used when mixing BMC.
Adding more styrene lowers viscosity but causes the moulded BMC to become brittle.