Tara, S. and Tarigan, C.U. 2026. DEVELOPMENT OF AN E-BOOK ON INNOVATIONS IN HAIRCUT DESIGNS, SIN BUTTERFLY, SIN REBEL, AND SIN LAYBOB TO SUPPORT HAIRDRESSER COMPETENCY. Journal of Beauty Science and Applied Cosmetology. 2, 1 (Apr. 2026), 18–27. DOI:https://doi.org/10.21831/jbsac.v2i1.2788.