Just to be clear ,spectra isn't composite material, unless you consider laminating wood together to be composite.
It isn't as dense as the stabilized material, probably about as heavy as walnut lumber.
SpectraPly wood is made in the USA from veneered layers of premium yellow birch that have been brightly dyed. Spectraply blanks offer a unique turning experience that yields high quality, vibrant projects! The veneers are dyed under extreme pressure for full penetration of the dye throughout the wood. After drying to 5% moisture content, they are then laminated in a radio frequency press for an unfailing bond with a perfectly consistent lined appearance. You'll enjoy vivid color, easy turning, and excellent stability. SpectraPly wood is easiest to use with sharp cutting tools. It glues easily and takes a variety of finishes; however spray on finish will ensure clearer color delineation.