Revenue at Quarto Group rose 6% in 2015 over 2014, to $182.2 million, while net profit increased 2%, to $9.3 million. Quarto chairman Tim Chadwick said 2015 was the most profitable year in Quarto’s history and that, with the company fulfilling his vision of attaining financial stability, he will step down as chairman this spring after a four-year run.

Chadwick will be succeeded by Peter Read, currently a non-executive director of Armstrong Ventures plc, Concha Plc, Quayle Munro Holdings, the Professional Cricketer’s Association, and the Royal Automobile Club.

The sales gain at Quarto was led by growth in a number of areas. The publisher saw a 41% jump in its children’s unit and, at $32.4 million, sales of children’s books now comprise about 22% of all revenue. The purchase in 2015 of U.K.-based Ivy Press also made a greater-than-expected contribution to Quarto. Quarto Group CEO Marcus Leaver said he was particularly pleased with how well the company's global sales and marketing operation performed in the year.

The company’s U.S. division, Quarto Publishing Group USA, had a solid year with revenue up 13%, to $72.4 million, and adjusted operating profit rose 35%, to $8.9 million. The increase was led by sales of adult coloring books, particularly those released by the house's Race Point imprint. Quarto U.S. publishes for a number of niche markets and the company continued to find new channels to carry books. Backlist, which has long been the backbone of the U.S. division, also did well in the year; backlist titles accounted for 71% of revenue in the States, up from 70% in 2014.

Continuing its strategy of making niche purchases, Quarto bought The Harvard Common Press in February 2016 and Quarto said that it will continue to look for acquisitions both in the U.S. and U.K.

Quarto said it expects overall earnings to increase in 2016 with sales expected to be strongest in the second half of the year.