Culley recorded his third suite of songs, Phosphor, in Kraków, Poland, and at Perring's studio on Jura, Scotland once again. The album features the upright bass playing of Ash Johnson, and Perring on percussion, harmonium, and with backing vocals, alongside guest performances from Simon Edwards on psaltery, drummer Phillip Harper, and the singer Melanie Pappenheim.
It was released on 8 July 2013 and was highly praised. Paul Sexton of BBC Radio 2 said 'Phosphor is an excellent album with more than a hint of Kelly Joe Phelps about it.'
Soundblab.com awarded Phosphor 10 out of 10, calling it 'one of the finest alternative albums so far this year.' The Italian website
Ondarock.com also lauded Phosphor, saying 'Phosphor is a valuable antidote to the poverty of inspiration and courage of many so-called heroes of the indie singer-songwriter genre.' It received airplay on BBC Radio 2, Radio Krakòw, and Resonance FM, London, where he played a live session.