Young graffiti artists – or vandals – can now carry the tools of their trade without fear of arrest.

Citing the First Amendment, a federal judge – who once was counsel to Mayor Dinkins during the graffiti scarred years of the early 1990s – yesterday suspended enforcement of part of a recent law that makes it illegal for 18- to 20-year-olds to buy or carry spray paint or broad-tipped markers in public areas. The law, which took effect January 1, was part of a package of anti-graffiti legislation aimed at preventing vandals from scrawling on subways, storefronts, and public buildings in the city.

Judge George Daniels of U.S. District Court in Manhattan ruled that the law placed restrictions on the First Amendment rights of a different group: young artists who use spray paint or large markers in their works.

“It initially appears unreasonable to tell a young artist that they have the right to express themselves in the manner they wish to express themselves, but to set significant and unreasonable restrictions as regards their ability to obtain the tools to make their art,” Judge Daniels said in a lengthy ruling.

Judge Daniels’s order suspending po lice enforcement of the law will go into effect this Thursday and is effective until a lawsuit challenging it is settled.

The lawsuit, which is backed by fashion designer Marc Ecko, was filed last Tuesday on behalf of seven graffiti artists who claim the law has restricted their access to the materials they require, or led them to fear arrest as they go about their day with spray cans in their possession.

Four of the plaintiffs were present in court yesterday. One, Vincent Schiano, 20, said in an interview that people pay him to decorate their bedrooms with graffiti. The city law has caused him trouble in obtaining spray paint at times, he said, forcing him to finish projects late.

In his opinion, Judge Daniels gave considerable thought to the concerns of the plaintiffs and others affected by the law.

“Say I am a 20-year-old art student, I have just moved here form California and all I want to do is paint,” Judge Daniels said. “How do I do that? I’m an artist but nobody can sell me art supplies. I can’t paint anywhere but in my own house.”

The law makes it illegal for 18- to 20-year-olds to purchase spray paint, broad-tipped markers, and etching acid, and to carry those three items in public. When he signed the law into effect, Mayor Bloomberg praised this anti-graffiti effort and others as simple common sense.

Judge Daniels’ order does not extend to the part of the law that prohibits 18-to 20-year-olds from possessing or buying etching acid.

In court, the city’s position has been that art students should go without those materials in the name of the greater good.

“It does not relate to art, to the First Amendment,” the city’s attorney, Virginia Waters, said of the law. “It relates to these tools. People don’t always get to express themselves in the way most convenient to them.”

But the lawyer for the plaintiffs, Daniel Perez, has said that the City Council member who drafted the law, Peter Vallone Jr., a Democrat of Queens, has an open hostility toward “graffiti art,” even when it is unconnected to vandalism.

“I don’t hate artists, but I have an intense dislike for vandals who deface other people’s property,” Mr. Vallone said in an interview last week. “No art student’s world is going to end because they can’t carry spray paint in their backpack.”

In a statement issued yesterday, Mr. Vallone said: “This is a minor bump in the road to a cleaner city. We haven’t presented our case and once we do I’m sure the judge will see the necessity of this law.”

Like Mayor Giuliani before him, Mr. Bloomberg has made graffiti a leading issue in his “quality of life” campaign. Last year, he used the occasion of his State of the City address to announce the creation of an 80-member anti-graffiti task force. He has called graffiti ” an invitation to criminal behavior.” Although a Bloomberg spokeswoman declined to comment on yesterday’s ruling, the mayor’s staff in the past has spoken of an ongoing “war on graffiti.”

Although Ms. Waters said that 871 people have been arrested for various graffiti violations in the first four months of 2006, the law in question has gone largely unenforced.

Only five people have been issued police summonses under the law, which carries a possible penalty of up to 15 days in jail for carrying spray paint or markers, Ms. Waters said.

Judge Daniels, who was nominated in 1999 by President Clinton, earlier served as a New York State Supreme Court judge and a criminal court judge. He served as counsel to Mr. Dinkins in the early 1990s.

At the end of yesterday’s court hearing, Ms. Waters, who has complained that the city did not have enough time to prepare its case, accused Judge Daniels of issuing his order too soon to have read through the city’s latest filing of court papers.