![Graffiti artists in Barcelona.](https://imagenes.elpais.com/resizer/v2/WVPEFK7LFIWUEFQCZ4ZLCOY5EI.jpg?auth=8f06f810e9b7fff919099694d62938643d79987eaa72624c424920b3c0a40d2f&width=414&height=233&smart=true)
Marketer by day, warrior by night: Meet the graffiti artists risking their lives to paint Spain’s trains
They meet up in stations, haunt hidden passageways and ignore no-entry signs. The infrastructure behind cities’ Metro and rail services has become as familiar to them as their own houses. Hooded and fast, they seek out carriages to spray as a cocktail of romanticism, art, adrenaline and risk courses through their veins. They are the ‘guerillas’ and this is their paint war