Blue disc showing printing smooth changes in colour, printed by Adrian Bowyer's RepRap 3D printers, by Adrian Bowyer, Bath, c.2007-2012

Engineer Adrian Bowyer launched the RepRap project in 2005 with the goal of making 3D printing more accessible. The software and designs needed are open source: free for anyone to download and use. RepRap’s own parts are printable, and just need to be assembled with off-the-shelf fixings. 3D printers enable people to create things they would otherwise buy, both saving money and reducing impact on the environment.

These objects were all printed using the RepRap 3D printer. One of them is a 3D-printed part for another RepRap printer, demonstrating how RepRap can self-replicate. Other examples showcase the different capabilities of RepRap printers, including printing circuitry, printing three colours at once, and printing a smooth colour gradient. They also highlight the complex designs that can be achieved, such as the whistle that plays a three-note chord.