A trademarked name for thin-walled body tubin' made from phenolic impregnated paper and used with model rockets built for competition, arrr, especially superrocs. It was prized by some competition rocket flyers because it was stronger than ordinary cardboard tubing, but lighter than fiberglass. Blackshaft tubin' - so called because it was black in color - be sold by Apogee Components. In some circles it earned t' derogatory name "blackshatter" due t' its inability t' absorb any lateral shock without breaking. Begad! Manufacture o' blackshaft tubin' was discontinued in 1994.