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

https://avasnewinsights.inkharbory.com/posts/will-floral-wire-work-for-a-storage-box-handle-or-will-it-snap

Upgrade your reclaimed boxes and bags by adding sturdy 2-3 mm galvanized wire handles. Drill 3 to 3.5 mm holes for a snug fit that won’t tear your materials