[14][15][16] Lead single "Lille", released on 25 August 2008, became an airplay hit on Irish and American radio stations.

[18] The admiration of Jason Mraz led to Hannigan supporting the Grammy-nominated Californian singer-songwriter on a 42-date US tour in late 2008.

[20] Sea Sew was released in the United Kingdom in May 2009, where The Daily Telegraph described it as "wonderfully creaky and raw", a record of "welcoming intimacy and ear-pleasing consistency".

[21] Prior to its release in Ireland, Hannigan previewed tracks "Lille", "Pistachio", "Some Surprise" and "Sea Song" on her MySpace page.

[23] The album also features musical personnel such as Donagh Molloy, Tom Osander, Shane Fitzsimons, Lucy Wilkins, Vyvienne Long and Gavin Glass,[24] whilst Cathy Davey and Rhob Cunningham provided backing vocals on some of the songs.