The trick is to treat the box like a small map. Place the secret slot where the line of sight is broken—usually at a seam that isn’t the obvious one. If you line up the front and back panels at a 45‑degree angle, the corner joints become the least noticeable. According to Section 3.2.1 of the Surveillance Manual, the probability of detection drops when the hidden area is aligned with the natural grain of the material. So, a snug pocket just under the top edge, flush with the lid’s crease, gives you a high‑yield spot with minimal exposure. That’s the pattern most collectors use.

For wood, pine or spruce have fine, regular grain that lines up well with a 45‑degree cut, so the pocket edge blends into the board. In cardboard, corrugated panels with a uniform flute give a subtle ridge that hides a pocket under the outer layer; a matte finish is safer than a shiny one, because glare can reveal the seam. According to the Surveillance Manual, a light‑tone varnish over the grain can diffuse reflections and reduce the chance a casual glance will notice a change in texture. Try the grain‑aligned pocket and see if the light catches it or passes over.