In this video I break down 5 easy ways to make super strong cardboard connections—some with hot glue, and one that doesn’t even need glue at all. I start with my toothpick method for connecting cardboard end-to-end. The big idea is simple: create the holes first, then add hot glue near the top of the toothpicks so the cardboard pushes the excess down and locks everything in. It’s surprisingly strong, and you can flatten or add extra glue on top if you want to beef it up even more. Then I talk about getting better results out of hot glue by using high temperature (if your glue gun can switch). High temp gives you longer working time, helps the glue seep into gaps, and makes for a stronger bond—especially on big connections. After that, I show how adding an extra bead of glue down the seam can turn a normal corner or T-joint into something that can actually hold weight (and yes, I’ll sometimes wet my finger to smooth the bead once it cools a bit). Finally, I show a slot joint that supports weight mechanically, and a barbed “no-glue” method that locks in place—just pay attention to cardboard grain direction for the strongest flaps.