UPS Recommends 200# Boxes over ETC boxes for shipping except for really lightweight shipments. The UPS strength guideline is: Max weight in a 32 ETC box 30#; Max weight in a 200# single wall box is 40#; Max weight in a 275 single wall box is 65 pounds; Ma weight in a 275 double wall box is 80#; Max weight in a 500 pound double wall box is 140#
Bubble Wrap is commonly purchased with Shipping Boxes. Other cushioning fill options include: