Ryan Gilhooly, 18, left his "tag" all over the city including at various train stations, inside trains and at Bearsden Academy.
The teenager sprayed "RAIO" and "CHS" - which stands for Causing Havoc Squad - in a spate of incidents between September 2012 and December 2013.
Defence lawyer Matthew Berlow said that according to expert Colin Saycell, graffiti is an addiction.
At Glasgow Sheriff Court Gilhooly, from Knightswood, Glasgow, admitted 18 charges including eight charges of "maliciously damaging" various places using spray paint, three graffiti charges of using a marker pen and seven breaches of bail by entering train stations and trains when instructed not to.
Among the places Gilhooly spray painted his "tag" on was a shelter at Drumchapel train station, a wall at Partick train station, a van at Yoker Depot and an underpass and wall at Hyndland train station.
He also targeted a wall at Bearsden Academy with the vandalism.
Procurator fiscal depute Angus Crawford said most of Gilhooly's offending involved railway property.
He said the teenager is described as a "prolific graffiti writer".
The total amount of damage caused by Gilhooly's crimes was £6706 and specialist cleaners had to be hired to clean the damage.
Sheriff Bill Totten deferred sentence on Gilhooly until next month and although he has been on remand since December for his crimes, he was released on bail.
The sheriff said: "If you have any sense of family responsibility or affection, or duty to your family, stop this because if you don't stop it I will have to send you to detention."