A US footwear startup is selling new shoes that aren't new at all. Like the Adidas x Parley, Rothy's shoes are knitted using yarn made from recycled plastic bottles. They also boast carbon-free outsoles, insoles and packaging that are recycled and can be fully recycled when no longer needed.

Rothy's is based in in San Francisco, California, and says its shoes are the result of three years of research and product development and are the first line of fashion footwear to make use of a three dimensional seamless knit process.

To begin with, the yarn used to knit the shoe uppers is made entirely from certified polyethylene terephthalate (PET) bottles. These are stripped of any caps and labels, hot washed and then processed into the filament fiber that becomes yarn. The yarn is treated with a wicking agent to drive moisture away from the foot.

The yarn used to knit the shoe uppers is made entirely from certified polyethylene terephthalate (PET) bottles

The result is said to be a soft fiber that creates a breathable upper, with around three recycled bottles going into each shoe. Using a proprietary process, Rothy's machine knits the shoes into their 3D shape, helping to minimize waste resulting from cut patterns, irregularities and defects. The upper is then heat-set into its shape using "lasts," or molds, and combined with the outsole and a cushioned insole to complete the shoe.

Rothy's inaugural collection is available in two styles and in 17 different color combinations. They are also machine washable, if only occasionally. At the end of its wearable life, each pair of the shoes can be recycled. Customers need only download a shipping form online and send the shoes to Rothy's recycling partner PLUSfoam.

Rothy's launched last month. Its two The Flat and The Point styles will retail for $125 and $145, respectively.

Source: Rothy's