The Archibald Prize requires artists to depict a real, living sitter, but Sean Layh read that rule and questioned whether his subject needed to be, or not to be.

The 30-or-so handlers, packers and hangers at the Art Gallery of NSW (AGNSW) proclaimed the Melbourne artist the winner of the Packing Room Prize, which runs adjacent to the Archibald, on Thursday.

Mr Layh said his painting, The tragicall historie of Hamlet, Prince of Denmarke, depicts more of Shakespeare's doomed Danish royal than it does of its real sitter, actor Jacob Collins.

"Hamlet has been one of the richest pieces of cultural inheritance we have in the arts," he told AAP.

"You often don't get a portrait of Hamlet - he's not a living Australian figure, and that's probably where that difference comes from."

The large oil painting depicts Collins lying, limbs splayed and tangled through bedclothes, in the centre of a roomy scene, much of it empty and in shadow.

But, to hear the packers tell it, the portrait's appeal stems from the fact it's really quite crowded.

"It's three people in this picture ... you've got Hamlet, you've got Jacob and you've got Sean," packing room staff member William Newell told AAP, adding it was very different to previous years' selections.

Debuting in 1991, the Packing Room Prize is a democratic contest which Mr Layh's painting won in a landslide, staff said.

"You don't need any words to go with it," packer Alexis Wildman told AAP.

"It draws you into the drama of the work ... I couldn't stop looking at it, honestly."

After being spellbound by Collins' performance as Hamlet in a 2024 Melbourne production, Mr Layh knew he at last had a subject and story worthy of Australia's most famous art award.

Many of the packers who award the packing room prize are artists themselves, with Mr Layh saying it was "deeply satisfying" to be recognised by people he considers his peers.

"When you do a painting like this, a part of it is very much trying to kind of talk to other artists," he told AAP.

His portrait is one of the more than 2500 total entries submitted for the 2026 Archibald, Wynne and Sulman prizes, which - discounting 2020 when the gallery extended the deadline - is a record.

More than 1000 of those were submitted for the Archibald Prize, of which just 59 finalists will hang in its most popular annual exhibition.

A little under half of the artists selected are first-time finalists.

The winner of the main Archibald Prize, who'll take home $100,000, will be selected by AGNSW's board of trustees and announced on May 8.