Since I live in a tiny camper roaming around, I need something portable and solid enough to protect against damage, water, etc.

I started with a little Vaultz box that holds around 450 4x6 cards (with a handle I bolted onto the lid to make it easy to carry around).

It's getting close to being full so after a bit of exploring various solutions (including this wonderful page), I ended up going with a small toolbox from the hardware store (specific link: https://www.lowes.com/pd/Klein-Tools-MODbox-Small-Toolbox/5014282951). It will hold 4,500 cards and is stackable (& latches onto box below) should I need another one.

I came across several other similar toolboxes, some smaller, that can do the job for those who might be looking.

Thanks for sharing all you do!

Ray