Makarovic (1939) has presented herself as a mature and confident narrator already with her first collection of fairytales for children "Miska spi" (Sleeping Mouse), which brought her the Levstik Award for children's literature in 1973.
Another Levstik Award followed in 1975 for a series of children's books, including "Pekarna Mismas" (Bakery Mismas), which was republished this year.
The book brings an original version of a contemporary animal tale into Slovenian literature, which is on par with the world's masterpieces in terms of quality, the judging panel said.
The main Levstik awards this year go to two unique artists, who are in a way connected through their uniqueness, said Andrej Ilc, the editor of publisher Mladinska knjiga, which has been giving out the award since 1949.
Both Makarovic and Gatnik started their careers in the 1970s and have even worked together on some projects, the most recent being the rerun of "Bakery Mismas", which was illustrated by Gatnik.
Makarovic commented on the award for the STA by saying that she "is always the same person, same author and that her literature knows no particular deviations".
"I never wrote Partisan trash under the previous regime, like some who are now writing Catholic trash, but this is none of my business. I am taking my own path and must always be true to myself, because the primarily duty of a human being is to be true to oneself and one's talents," Makarovic said.
The jury described Gatnik, who won the Levstik Award for illustrations already in 1982, as one of the "pillars of Slovenian illustration tradition".
"It's good if others find at least some pleasure in somebody's work if not usefulness," said Gatnik, who last year won the highest recognition for cultural achievements in Slovenia, the Preseren Prize.
In a statement for the STA, he said he was not clinging to standards in his work but tackled every project individually.
This year's Levstik Award for children's literature meanwhile went to Majda Koren for "Mici iz 2. a" (Mici from 2nd Grade) and to Damijan Stepancic for his illustrations of the book "Zgodba o sidru" (A Story About an Anchor).
Koren convinced the jury with the unity and "indisputable quality of 20 stories" in which the author "convincingly portrays everyday life in school", which offers insight into child psychology.
Stepancic's original illustrations meanwhile attest "full artistic maturity and autonomy", according to the judging panel.
Conferred to over 100 authors so far, the biennial award is named after Fran Levstik (1831-1887), a writer, critic and essay writer. One of his most famous books is "Martin Krpan", a tale about a robust Slovenian peasant and a smuggler of salt who saved the Vienna court from an enemy.
The awards will be conferred at a ceremony in Ljubljana this evening.