The target was a transparent rigid board under a PC: an acrylic sheet or clear acrylic plate.
1. Shopping became mechanics
Candidates around A3 size—roughly 300×400 or 300×450 mm, sometimes about 5 mm thick—appeared. Then came the real question: “Why would that make it flat?”
2. Flat ≠ level
A rigid flat sheet bridges small bumps and spreads the PC's load across a wider area, useful on carpet, bedding or another soft surface. But if the floor slopes, the sheet slopes too. Flat describes surface shape; level describes orientation relative to gravity.
3. Match solution to problem
To stop feet sinking, use a rigid surface. To correct actual tilt, use height adjustment, shims, spacers or adjustable feet.
4. Conclusion
Acrylic can smooth local unevenness; it cannot automatically correct slope. A tiny shopping question ended as a useful distinction between flat and level.
