Catalina Alvarez was visiting her father's clothing factory when she saw a box of brightly-coloured cloth samples in a rubbish bin.
The small sheets of material may have been rejected by her dad, but for Catalina they immediately sparked the idea for a business.
"For me it was like 'wow', I have found treasure, because I knew all the things I could do with these little pieces of fabric," she says.
Excited, the fashion design student in the Colombian city of Medellin phoned her classmate Mariana Hinestroza to share her vision.
The pair were soon sat at Catalina's grandmother's sewing machine, piecing the scraps into bikinis. It was back in 2003 and Catalina and Mariana were both 22.
Fast-forward to 2018 and their company - Agua Bendita (Holy Water) - sells its kaleidoscopic women's swimwear to 60 countries, with annual revenues of $7.5m (£5.4m).
Helped by a big break in 2007, when one of its designs was featured in Sports Illustrated magazine's annual swimsuit edition - something akin to winning an Oscar in the swimwear world - the Medellin-based company now ships more than 150,000 bikinis per year, plus 50,000 other items of beachwear.
The fact that Agua Bendita is based in Medellin may raise some eyebrows given the city's violent past. Ravaged by drug gang violence in the 1980s and early 1990s, it was then one of the most dangerous cities on the planet.
However since the drugs gangs were moved on, and following major regeneration work over the past two decades, the crime rate has fallen substantially. Medellin has been transformed is now a bustling city with a buoyant economy.
At the traditional Colombian-style red tiled house that is Agua Bendita's headquarters in the green hills on the outskirts of Medellin, Catalina and Mariana run some of their latest designs past the company's sales and marketing staff, mostly young women.
Amid whirring sewing machines and fluorescent lights, a towering model twirls in a bikini made of a light pink material splashed with scarlet flowers.
With little or no space for logos on its teeny-weeny bikinis, Agua Bendita has worked hard to maintain a distinctive signature style, and this two-piece is typical of its bright, multi-coloured designs, featuring Colombia's tropical plants and birdlife.
While the company now has a 120-strong workforce across its head office and cavernous dispatch warehouse in Medellin, since 2005 most production work has been outsourced to scores of small workshops that service the city's vibrant clothing industry.
For the trickiest finishing touches, such as intricate embroidery and beadwork, Agua Bendita sends its clothes to a group of chatty seamstresses who work at their homes about an hour's drive away in the countryside. The company says that in total, it provides work for some 900 people not directly employed by the business.
Growing slowly for its first three years, in 2007 Agua Bendita's sales shot up thanks to Catalina and Mariana hiring a small stand at a swimwear trade fair in 2007.
The industry took notice, and the company got its big break in Sports Illustrated, further helped by the fact that in the photo shoot its bikini was worn by Israeli supermodel Bar Refaeli.
"The day that edition came out I had more than 400 or 500 messages from people who were interested in the swimsuits," says Catalina.
"They were not from Colombia, they were from all around the world."
As Agua Bendita has continued to expand, co-owners Catalina and Mariana have brought in a chief executive to look after the financial side of the business while they lead they design work.
Chief executive Alejandro Ceballos admits that the company had looked into moving production abroad, to India, China and Bali, but ruled it out.
"It didn't make economic sense" he says.
"There's not such a big difference in the pricing, but also we do not want to be investing in developing suppliers abroad.