both. seriously. i didn't think i needed both of them, but i got them to complete my black/neutral palette, and they're probably my 2 most used shadows. they do completely different things, and complement different colors. carbon is good as a liner, or to tone down and mute brighter shades, black tied is good if you want an intense, high impact black or smoky look. i didn't think i'd like CARBON (edited: im a moron, i originally said black tied) since its a matte, yet its SO easy to blend and work with.