Poetry and illustrative book entries were among the highest calibre in this year's Montana Book Awards according to one of the judges.

The level of poetry entries was "outstanding" and the judges could easily have picked five finalists instead of three said judge and journalist Lynn Freeman.

"It was one of the killers, one of the ones (categories) we had sleepless nights over."

Ms Freeman said deciding on the illustrative category finalists was also "heartbreaking".

Meanwhile, there were only four fiction finalists chosen this year, there were normally five.

Ms Freeman said the four were "outstanding books and, while there were other great books, we did not want to dilute the Montana (finalist) sticker by promoting a fifth.

"Those four books were just so good that they really merited the finalist sticker."

She said there had been a lot of discussion about choosing just four and said the quality of all 35 fiction entries was good.

The fiction finalists this year were all women, including debut novelist Mary McCallum with The Blue and Alice Tawhai with her second story collection Luminous.

Ms Freeman said the books were judged on their topic, authorship and publishing.

She said many of the finalist books were "in danger of missing out (on attention)" before being chosen and said there were no obvious winners.

"There were many new writers chosen, even though there were some big names entered, which signals the awards are open to new and emerging authors and not dominated by very experienced writers," Ms Freeman said.

She said while this was not why the books were chosen it was an encouraging sign.

In total, the three judges reviewed 221 books from eight categories to decide on the finalists.

The winner of each category receives $5000 and is eligible for the Montana Medal for Non-Fiction, or the Montana Medal for Poetry or Fiction which carry a prize of $10,000.

The winners will be announced on July 21. The winner of the poetry category will be announced on July 18.

Last year, Lloyd Jones won the Montana Medal for Fiction or Poetry, the Readers Choice Award and the fiction category for his novel Mister Pip.

Audrey Eagle won the Montana Medal for Non-Fiction with her work Eagles Complete Trees and Shrubs of New Zealand.