The biochemists out there will be wondering why someone's daubed a giant start codon along the railway tracks.
For everyone else, ATG, otherwise known as 'Ahead of the Game', are a collective of graff writers who seem to spray predominantly in the north-west of London. They're well-named, offering a brighter, bolder style and beautifying otherwise mundane spaces along rail tracks and rooftops. According to a wonderful article in the Camden New Journal, they achieve the look by preparing the walls with emulsion.
With emulsion on first you could paint crisp colour pieces that really stood out like a sticker or an advert. We hoped other people might start doing stuff like that but they didn’t.
These examples can be found underneath the rail Bridge on Mill Lane, NW6 and alongside the Thameslink tracks west of the O2 Centre (Finchley Road).