Otani et al. described the use of an alkali-modified solution of lignin to produce carbon fibers. Later studies have focused on producing carbon fibers derived from modified-lignins by melt spinning of steam-exploded lignin, organosolv lignin and hardwood kraft lignin and . In a recent study, fractionated softwood kraft lignin in combination with hardwood kraft lignin was found to be capable of continuous melt spinning and fast stabilization. But the as-spun lignin fibers were thick (aprox. 100 μm) with carbonized fibers being about 50 μm in diameter, and no tensile properties were reported for those fibers.