Low-thickness technical part designed to quickly and comparably check how the first layer is deposited in different areas of the print bed. The matrix allows for observing variations in squish, line continuity, and adhesion without consuming much material, making it useful after leveling the bed, adjusting the Z offset, changing the print surface, or modifying the slicer profile. Each sample must be interpreted as a visual reference: separated lines usually indicate excessive height; a very squashed, rough, or translucent surface may indicate a nozzle that is too close. The model does not automatically correct mechanical problems, dirt, bed deformation, or poorly calibrated flow.