The first study of hundreds of poems and pictures scrawled on the walls of one of Australia's oldest convict prisons has shed light on the inmates' day-to-day hardships.

Archaeologist B'Geella Romano has documented almost 800 graffiti images at the world heritage-listed Fremantle Prison.

Some of the graffiti has dark themes. ( Supplied: B'geellla Romano )

The result is a vast database of poems and pictures, some rude, some violent, some tender and some political.

"You get the cartoons and the fun pieces, which were I think to alleviate boredom, and as a bit of fun to lift their spirits," Ms Romano said.

"But then in opposition to that you get very dark images of skulls, and needles, and swastikas, so this graffiti is doing all different things.

"It's messaging to other inmates, it acts as a sort of catharsis for the prisoners, and it's speaking of their identity."

Notorious prison closed by riots

Fremantle prison was renowned for its harsh conditions. ( Supplied: B'geela Romano )

The prison — with its distinctive high limestone walls — was built in the 1850s to house convicts, and went on to house prisoners for 140 years.

It was closed in 1991 after a string of riots and protests that highlighted the harsh conditions at the facility.

Writing or drawing on the cell walls was not permitted, but pictures still flourished in hidden corners and on the back of cells doors.

The rules were relaxed in the last few months of the prison's operation, allowing graffiti and artwork to spread across the white-washed walls of the tiny cells.

One prisoner writes:

"For 16 hours a day we're locked in here, with the cockroaches and the rats, and with our shit bucket. Could you handle it? And would it change you?"

"The graffiti paints a really interesting picture of daily life, and you get the feeling it was a very depressing place to be," Ms Romano said.

"The graffiti is saying it's dirty, it's hot, we hate it and we want to get out, so it's pretty clear it was a really unpleasant place to be."

'Secret' corners reveal inmates' intimate lives

Some of the art expresses tenderness and hope, while for some prisoners it was just a way to alleviate boredom. ( Supplied: B'geella Romano )

Some of the inscriptions are disturbing and violent, with one prisoner penning a long ballad involving sexual violence.

But there are tender moments too, with the names and initials of girlfriends on the outside recorded within clumsily drawn hearts.

Ms Romano said there was a clear distinction between graffiti written as a statement to guards and prisoners, versus more personal words and pictures written in secret spots out of public view.

"In other private spots, we've got more private internal things going on, or things that need to be hidden," she said.

"You might be messaging to your cell mate, threatening them or making fun of them, or having a joke with them," she said.

The graffiti gives an insight into the power-play and violence that characterised daily life.

In one cell, a prisoner has scrawled the names of the men he believes "narced" on him, and describes how they will die a "slow, painful death".

Another scrawl threatens the judges that put him away.

The archaeological study is part of ongoing efforts to record the history of the Fremantle Prison, which is part of a network of 11 world heritage listed convict sites in Australia.