Red Lion Books in Colchester teamed up with Essex Libraries to donate 500 ex-World Book Day books from its stock for fathers to give to their children to encourage reading.
Cllr Anne Brown, the Cabinet Member responsible for libraries, said: “The sessions offer a less daunting way for children to visit their fathers in prison, away from the large visiting hall.
"Research has shown that maintaining family relationships for a parent is in prison plays a significant role in reducing the likelihood of reoffending.
"We are very grateful to Red Lion books for their donation as it means children will be able to continue reading after the visit."
The owner of Red Lion Books and trustee of the Essex Book Festival, Peter Donaldson, and Louisa Steel, manager of the library at HMP/YOI Chelmsford, had the idea at a recent Festival board meeting.
One eight-year-old girl said of the latest session: “It was great. I had the best time with my dad. Thank you.”
One of the fathers wrote to the library supervisor after the latest event.
He said: “To the lovely under-appreciated ladies of the library, thank you so much for everything this afternoon, it was perfect. I know that you put a lot of thought and time into making today very special and let me tell you, special it was.
“My lovely daughter has only been to the prison once before and she hated it, so for her to come today was both a big deal for her and for me.
“Once in six months is a very long time and is even harder for her. So thank you for making it so special. From the bottom of my heart thank you all so much.”
The Essex Book Festival takes place every March with events happening in venues across the county.