It's something he had been planning to do for quite some time, but the thought of accumulating trash for a project seemed like a "scummy activity." So he held off for a while until one day he discovered a "baggie" near his home with an intriguing black widow spider design. He picked it up and began what he now calls, the "Discarded Drug Baggies" project.
Giannopoulos had a goal in mind to create a series that was more focused on art than his traditional reportage work.
"This project was as much, if not more, about the beauty I saw in these little bits of trash as it was about what they represented," said Giannopoulos, a 35-year-old photographer based in London.
"This is first and foremost a project intended to make something aesthetically engaging from pieces of trash that the general public are mostly unaware of. To me they are really interesting pieces of street art that are loaded with meaning and questions. They're almost like tags of drug users. Or minute markers of an addiction made public."
'One man's trash is another man's treasure'
When he finds a baggie, Giannopoulos plots the exact location on a map in an attempt to chart patterns of drug use across the city. He focuses on areas close to where he lives, on the outskirts of London and South East London.
Most baggies are found in poor areas, but he also finds baggies in wealthier areas with large, open public spaces. He has discovered baggies in parks, near bars and nightclubs, and even next to schools and playgrounds.
After he collects a baggie, Giannopoulos photographs it against a white background.
"I like the term 'One man's trash is another man's treasure,' " he said.
During his three years of hunting for drug baggies, Giannopoulos has found 67 variations of designs and graphics. He wanted to map the baggies to see whether there were any patterns connecting different designs to certain locations, but he hasn't found those links yet.
"Some designs would stop appearing and other new designs would take their place from year to year," he said. "There isn't an area that has more Bob Marley baggies than Union Jack baggies."
The most prominent baggies are the ones with leaf designs, bulldogs, machine guns and plain bags with a green reseal strip.
Making the invisible, visible
Giannopoulos is passionately curious about the underlying stories of these dirty, discarded baggies.
"There are a number of ways that you can read into these artifacts," he said. "Whether that is questioning where they came from, the journey they took to get where I found them, what was in them, who it was that consumed the contents. What was their story? Are they a casual, social user or is their story one of dependency? And you can also ask bigger questions about public drug use in London."
Giannopoulos says most of the baggies he finds allude to or contain obvious remnants of marijuana. This isn't surprising, since cannabis is the most commonly used drug in England, according to national statistics from the 2014 to 2015 Crime Survey for England and Wales
He also notes that many of the designs on the baggies relate to weed in some way.
"They'll either have a cannabis leaf displayed somewhere in the design, or will have something that is in the design that is synonymous with cannabis culture, for example Bob Marley or lips with a joint," he said.
His intended end result for the project was to create a large digital collage of all the baggies to illustrate drug culture in London and the ubiquitous baggies that symbolize these illicit acts. He never had a particular number in mind, but when he recently finished the project, the final total was ironically, and entirely unintentionally, 420 baggies.
Giannopoulos is working with the Ben Oakley Gallery
, a commercial art venue in South East London, to create an exhibition that will be displayed this June.
"London is really no different to any other big city. There are plenty of drug users -- public and private. I think that this project has made some people more aware of these baggies," he said.
"In a way, it has made something that was always there but invisible, now visible. I've had people tell me that prior to seeing the project they had never seen one of these baggies before, and now they see them everywhere."