Making paper out of rock isn't just a novel idea — it saves water, is both recyclable and biodegradable and uses a mineral resource available anywhere on Earth.

TBM Co., a startup known for its technology that turns limestone into business cards, plastic folders and food containers, is seeking to raise another round of funding to expand overseas before it prepares for an initial public offering in a couple years.

Goldman Sachs Group Inc., trading house Itochu Corp. and Toppan Printing Co., Japan's largest printer by sales, have already invested in the manufacturer. TBM, which raised ¥1.6 billion and ¥3.1 billion in its latest two rounds, is looking to secure several billion yen, according to Chief Executive Officer Nobuyoshi Yamasaki.