When a packaging 3D model is dark when lit, it’s usually due to insufficient light intensity, poor placement, or materials that don’t reflect light well.
If the light is too dim, it won’t brighten the model. If it’s aimed at the back or side instead of the front, key areas stay dark. Matte materials like cardboard absorb more light than they reflect, so the model doesn’t bounce light effectively.
To fix it, increase light brightness, position it to face the model’s front or important details, or adjust your 3D software’s material settings—boost "diffuse" (color reflection) or "specular" (shiny highlights) for a natural, balanced look.