Upgrade your reclaimed boxes and bags by adding sturdy wire handles. Use 2-3 mm...

https://wiki-saloon.win/index.php/How_Much_Weight_Can_3_mm_Galvanized_Wire_Actually_Hold%3F

Upgrade your reclaimed boxes and bags by adding sturdy wire handles. Use 2-3 mm galvanized wire for strength and drill 3-3.5 mm holes for easy threading