Tel Aviv designers Gilli Kuchik and Ran Amitai have used magnesium, one of the lightest metals, to create a stacking chair that weighs just 2.5 kilograms.

Unveiled by Italian furniture brand Magis during Milan design week, the Vela chair plays to the strengths of its low-density material.

Whilst structurally strong and easy to work with, magnesium weighs 30 per cent less than aluminium. It can also be cast thinner, allowing for a much more slender design.

The designers wanted to "express that lightness" in a chair that is easy to move around and stack up, making it well suited to cafes and restaurants.

"After a comprehensive exploration of magnesium's properties and manufacturing possibilities, we decided that we wanted to deal with stacking as the main idea," explained Kuchik and Amitai.

"Due to magnesium's light weight, we thought that the best expression of lightness is to design a chair that is intended to be picked up," they told Dezeen.

The chair back features two cut-out sections, which the designers describe as "like stretchers through the back of the seat".

These provide the openings for the legs of any chairs to be stacked on top, as well as creating two handles for users to grab when they lift the chair. The chairs can be "infinitely and tightly" stacked in this way.

The lightweight chair is moulded and powder-coated, without the drainage holes typical of outdoor seating, and comes in six colours: silver, white, black, green, red and brown.

"Because we wanted the chair to be a visual fit for indoor as well as outdoor, we needed to find alternatives to elements that are specifically identified with outdoor chairs," explained the designers.

"For this reason, we designed the seat so that water cascades to the openings in the backrest and eliminated the need for draining holes in the seat."

The designers are hoping that magnesium may become an alternative to plastic for this sort of multi-purpose seat that can be used both inside and outdoors.

According to the designers, as well as being durable, magnesium can be recycled and is plentiful – it is the eight most abundant element in the earth's crust.

Kuchik and Amitai set up their multidisciplinary studio in Tel Aviv in 2009. Vela is their first collaboration with Magis, whose products also include the steel Chess furniture by Konstantin Grcic and the skeletal Milà chair by Jaime Hayon.