Tough laws designed to crack down on graffiti vandals will give judges the power to make offenders clean up the damage they cause, the NSW government says.

The laws will also see a doubling of the current penalties for graffiti vandalism.

Youths caught in possession of spray cans without a legitimate reason face a maximum six-month jail term.

NSW Premier Nathan Rees said the laws were tough, but necessary.

"In many communities, the very sight of graffiti makes people feel unsafe," he told reporters in Sydney on Sunday.

"Not only that, but it undermines community pride.

"The central thrust of this package is this - if you mess up, you will clean up."

Attorney General John Hatzistergos said magistrates would now have a wider range of penalty options to deal with vandals.

"One of the issues that has arisen when people pay fines is that sometimes those fines are paid by other persons," he said.

"It's important to get the message to those persons that this is a serious offence.

"One of the means we can do that is to be able to have those fines converted into clean-up work."

Mr Rees says there will be an annual Graffiti Action Day across NSW, beginning May 2, 2010, in a similar style to Clean Up Australia Day.

Opposition Leader Barry O'Farrell said the new laws were just a stunt.

"This is window dressing from Nathan Rees, tougher penalties are useless unless offenders are identified and brought to court," Mr O'Farrell said.

"The state government's own figures show that offenders are identified in less than a third of cases and only 10 per cent of graffiti attacks end up before the courts.

"Graffiti will remain a problem as long as the Rees government continues to starve communities across the state of the police resources needed to track down and identify graffiti vandals."

Mr Rees said the opposition was being inconsistent in their criticism of his government.

"It's one thing for the leader of the opposition to come out each day and get stuck into a government, but he has to put up an alternative.

"And on this one he simply hasn't done it, yet again."