MURWILLUMBAH artist Trish Callaghan has won the 2012 Border Art Prize for her work 'Portrait of the artist's father' and called her win an affirmation of her new work in a new medium.

"It was a wonderful surprise, I had absolutely no idea.

"People at the gallery didn't recognise the work as mine as I'm better known for my landscapes in pastel.

"What can I say, it's just a thrill," Ms Callaghan said.

Ms Callaghan received the $3000 prize at a function at the Tweed River Art Gallery last Friday when Border Art Prize judge, Museums & Galleries NSW chief executive officer Michael Rolfe announced his winning selection.

The first prize was funded by Tweed Shire Council and council's general manager David Keenan was on hand to officially open the exhibition of the 241 works selected to be displayed.

Ms Callaghan said the painting was one part of a series of 12 pieces in acrylic depicting her father with his working dog and was an exploration of a totally new medium.

The announcement of the winning painting was greeted by huge applause and elicited many positive comments.

"This is the best Border Art Prize I have seen.

"Obviously many entries are to different tastes but all of it is of a high standard," one regular visitor said.

Second prize of $1500, funded by the Friends of the Gallery, went to a colourful oil on canvas, Silva Nigra Singing, by Tweed resident Valentina Palonen while the $500 third prize, a cloud carved from Carrara marble titled Billow, was awarded to Clunes artist Geoffrey Cotton.