Imperfections meaning

Even the slightest skin imperfections had disappeared.

Dust and other particles can scratch the surface of your disk, causing imperfections in copying and playback.

The manuscript maps intended to be produced by photographic processes upon stone, zinc or aluminium, are drawn on a scale somewhat larger than the scale on which they are to be printed, thus eliminating all those imperfections which are inherent in a pen-drawing.

Artificial membranes are seldom or never perfectly semi-permeable - some leakage of solute nearly always occurs, but the imperfections of actual membranes need no more prevent our use of the ideal conception than the faults of real engines invalidate the theory of ideal thermodynamics founded on the conception of a perfect, reversible, frictionless, heat engine.

You know you're doing wrong, but you sort of admit to your own imperfections.