CONCORD, N.H. — A settlement has been reached in a federal lawsuit challenging New Hampshire’s prison mail policy, and inmates will now be allowed to receive some handmade drawings.

Prison officials had complained that inmates were getting the prescription drug Suboxone smuggled in via heavy, card-stock paper and hidden beneath stamps, stickers or layers of crayon drawings. The drug, which comes in a thin strip, is designed to treat heroin addiction but can also give users a high.

The Department of Corrections then banned drawings, post cards and greeting cards.

Following the ban, the state chapter of the American Civil Liberties Union in 2015 sued the department on behalf of an inmate whose 3-year-old son sent a Thanksgiving card to him that included drawings and the handwritten message: “I (heart) U DADDY.” The drawings were on coloring paper provided by the prison’s Family Connections Center.

The settlement, reached Sept. 14, allows only pen-and-pencil drawings, but no greeting cards or thick stationery. Photocopies of the cards or drawings made with other materials may be sent.

“Under the original policy we challenged, the state had eliminated one of the few ways young children could communicate with parents who are in prison,” Ned Sackman, who represented the inmate’s family, said in a news release Thursday. “The challenged policy was not only devastating for families — especially those who are low-income and live far away from the state prison — but also counterproductive.”

A message seeking comment from the department on the settlement was left Thursday.

When they announced the ban in the spring of 2015, prison officials said the department didn’t have the staff to manually scan hundreds of pieces of mail each day.

In its lawsuit, the ACLU said the department went too far and had created one of the most restrictive state prison mail policies in the country. It said the department’s own records show not one instance of Suboxone being smuggled in via a drawing or message written on regular-stock paper.

The department this year made other changes after several inmate drug overdoses at the state prison in Concord and a suspected drug use-related death at a housing unit in Manchester. Inmates haven’t been allowed to get bound packages of legal mail or have access to vending machines and board games from visiting rooms. Prisoners and visitors also are barred from kissing.

The department said in August that fewer inmates are testing positive for illegal drugs after it implemented its policies.