In this video I break down a question that quietly makes or breaks a lot of cardboard projects: are you using the right kind of cardboard for the job? I walk through what I actually see in real boxes—single face, single wall, double wall—and then I get into the flute “kinds” (A, C, B, E) so you can stop guessing and start choosing on purpose. The big idea is simple: different cardboard bends differently, holds detail differently, and shows corrugation differently—so the “best” cardboard depends on what you’re building. I explain how single face is awesome when you need to wrap cylinders because it bends easily in certain directions, but it won’t bend sideways very well. Then we move into single wall (your standard shipping box) and double wall, which I love for strength and thickness—especially because the two flute layers don’t line up, so it resists bending better. After that I compare A-flute (thick, great for big builds but ugly for tiny details) all the way down to E-flute (thin, clean, and way better for fine details). Finally, I cover chipboard (like cereal or graham cracker boxes): it’s thin, has no fluting, and it’s perfect for small details or covering corrugation when you want a cleaner look. If you want a quick reference, I made a free cheat sheet you can download and even cut out as physical samples.