Lotus-like paper/paperboard packaging prepared with nano-modified overprint varnish

Paper/paperboard has great advantages over plastics as packaging material in terms of cost and sustainability. However, the application of paper/paperboard packaging is limited due to their inferior water resistance performance. Here we report a functional overprint varnish prepared with the aim to significantly abate the wettability of the printed packaging. The prominent water repellency of the varnish is rendered by its unique nano-structured morphology, a technology bio-mimicking lotus surface. The frost formation on the applied packaging is also inhibited. Moreover, the transparency and the application process of the varnish are retained. We expect such varnish has high potential for expanding the application field of paper/paperboard packaging, especially for uses requiring a strict standard of water resistance.