"We worked on Blue Lines for about eight months, with breaks for Christmas and the World Cup," said 3D, "but we started out with a selection of ideas that were up to seven years old. Songs like 'Safe from Harm' and 'Lately' had been around for a while, from when we were The Wild Bunch, or from our time on the sound systems in Bristol. But the more we worked on them, the more we began to conceive new ideas too – like, 'Five Man Army' came together as a jam."
Blue Lines is generally considered the first trip hop album, although the term was not widely used before 1994.
The album reached No. 13 on the UK Albums Chart; sales were limited elsewhere. A fusion of electronic music, hip hop, dub, '70s soul and reggae, it established Massive Attack as one of the most innovative British bands of the 1990s and the founder of trip hop's Bristol Sound.
Music critic Simon Reynolds stated that the album also marked a change in electronic/dance music, "a shift toward a more interior, meditational sound. The songs on Blue Lines run at 'spliff' tempos – from a mellow, moonwalking 90 beats per minute ... down to a positively torpid 67 bpm."
The group also drew inspiration from concept albums in various genres by artists such as Pink Floyd, Public Image Ltd., Billy Cobham, Wally Badarou, Herbie Hancock and Isaac Hayes.