BRUSSELS (Reuters) - In the history of currency, earplugs have, unsurprisingly, never been widely used or accepted. So when a man offered Belgian artist Delphine Boël 10,000 earplugs for her print "The Source of Identity" at the Truc Troc contemporary art exhibit in 2006, her reaction was, "God, he's crazy."
Then she thought about it overnight - and became inspired.
"I phoned the guy the next day and I said, 'You've got the print, give me 10,000 earplugs and I'm going to make a work of art with it.'"
Unusual offers are the norm and part of the fun of Truc Troc, which is in its eighth year since restarting in 2004 after initial shows in 1975 and 1976.
The event's concept came from Belgian sculptor Mon de Rijck, who wanted to "democratize" art exhibitions through bartering.
Visitors to Truc Troc post an offer near a piece of art and the artist can choose which offer, if any, they want to accept.
Event organizers said on Sunday afternoon they were on pace for about 20,000 visitors, the same as last year, for the three-day event at Bozar, a Brussels fine arts centre.
The exhibition, which included a party with DJs on Friday night, was meant to attract young people and remove barriers to the traditionally expensive art world.
"Maybe some people come just to listen to the DJ or to drink some beer," said Mikhail Porollo, a photographer participating in the show. "But then at the end of the day, they walk through the exhibition, they know what's happening ... and then they interact with the art."
Most of the artists taking part are also young, just starting their careers and looking for exposure. The exhibition spanned a wide variety of media such as traditional acrylic paintings or photography to more avant-garde materials such as cardboard or metal street signs.
About 100 artists contributed 300 pieces for the exhibition.
Before Christmas, Delphine Boël, 43, completed a couple of prints with the each letter in the word "hypocrite" in a variety of bright colors.
In her living room, there is one version with a white background, "Endless Hypocrites," that says there is not just one hypocrite, but many. Boël showed "Private Thought" at this year's Truc Troc, with a black background and a slight twist.
In the centre of "Private Thought," Boël put a crooked gold crown on one of the Os - a nod to King Albert II of Belgium.
Boël has said she is the illegitimate daughter of Albert and her claim has been widely reported in the media. The palace has declined to comment.
Many of Boël's pieces are layered over this background.
"From my experience, I am going to build, and from that I am going to exhibit it and from that I am going to sell it," she said of translating her feelings into art.
"Private Thought" received more than 100 offers at Truc Troc, putting it among the more popular pieces at the event.
Porollo, 33, chronicled multiculturalism in his photography project, "Goddesses," from May 2010 to May 2011. He took portraits of 12 women in Brussels, all of whom were from different countries. He chose four photos for his first appearance at Truc Troc.
Porollo covered each woman in traditional clothing associated with their homeland, so only their faces are visible. He said the choice had little to do with religion and is meant to create a blank background and highlight their faces.
He edited each picture, of women from Europe, Africa, Asia and South America to make their faces perfectly symmetrical - a scientific ideal of beauty.
The photographer and painter, who comes from the northern Caucasus in Russia came away from Truc Troc pleased: the 250 pamphlets he had printed were gone by Sunday afternoon.
Belgian artist Jerome Considerant deconstructed three famous paintings as metal street signs, with two of his inspirations coming from the Royal Museum of Fine Arts in Brussels.
The "Tower of Babel" by Pieter Bruegel the Elder is imagined as an orange and black construction sign with the partly finished tower rising above busy workers. Considerant also simplified Jacques-Louis David's "Death of Marat" down to a few basic shapes, yet both works remain recognizable.
He also re-examines Theodore Gericault's "The Raft of the Medusa," which depicts the aftermath of a shipwreck whose survivors on a raft endured cannibalism and madness.
(Reporting By Eric Holmberg)