Argos is partnering with 3D printing expert Digital Forming on the project. The R&D project has also been supported by Innovate UK, a government-backed technology agency.
Using the newly launched website, budding designers will be able to select accessories from a range of 10 items initially, add their own personal touches, and then 3D printers will bring the designs to life.
Jewellery will be priced from £50 to £220 and the collection includes bangles, pendants, rings, cufflinks and earrings.
Neil Tinegate, head of digital innovation at Argos, said: "There has been a lot of excitement about 3D printing and we are just beginning to explore the mainstream application of these techniques.
"We are launching the site as a trial, to gauge how customers want to engage with it. We will assess results and learnings to inform future decision making in due course."
Lisa Harouni, CEO of Digital Forming, said: "We are excited by the potential for our customers to get creative in developing their own bespoke products. We are starting with jewellery, but see applications for lighting, homewares and other areas in the future."
She said: "We have used revolutionary manufacturing processes to power this website and we are excited by the potential to engage customers in a new way - by inviting them into the design process of their products."