Most of the box is used for outer packaging because of strong wall. Blue Yellow recommends single wall for weight up to 15kg and double wall for weight 15kg up to 30kg. But for fragile goods, Blue Yellow always recommends double wall from 1kg to 30kg for safety. Do not pack the goods more than 30kg in 1 box to avoid damage. Beside regular box, the paper also can make an innovative box such as display box, fruit container, beverage holder, strong and safety.