Forget the brown paper bag: green paper bottles are coming.

On Thursday, Danish beer company Carlsberg announced that it’s one step closer to introducing the innovative new sustainable packaging. The initiative aims to lessen the brand’s environmental impact, while also offering consumers a unique new drinking option.

The move follows last year’s news that Carlsberg would start selling beers in glued “snap packs,” while fellow beer company Corona began testing biodegradable six-pack rings made with plant-based fibers. Guinness also made headlines earlier this year when it revealed plans to reduce the amount of plastic used in the company’s packaging.

In the Thursday announcement, Carlsberg revealed two prototypes of the bottle. Both are made from sustainably sourced wood fibers, are fully recyclable, and have an inner barrier to allow the bottles to contain beer, according to the brand.

While the company has been working hard to test the prototypes since 2015, they are still a few years away from introducing the bottles to the market.

The company isn’t alone in its effort to go green. Carlsberg is working in conjunction with Absolut, Coca-Cola, and L’Oréal to develop paper packaging.