One of the games I received recently is Pandante, which I'm finding enjoyable so far and looking forward to playing with higher numbers of people.
I like the clean art design but there's a slight glitch - when the card
backs are flat red with a little white text (i.e. not patterned in any
way) even small defects show up glaringly on the backs.
As a result there are four cards in my deck that have manufacturing or
printing defects that mean that those cards are "marked". The one with
the white blob mark is a "1", the deeper red "birthmarked" card is a
"6", etc.
Example:

Camera doesn't pick it up too well but there's a white dot on one and a
"birthmark" of deeper/extra red ink on the other. They're both much
more obvious in person than the photo makes it look. A couple other
cards have less immediately apparent but still noticeable defects.
Interestingly if the card backs were patterned like most decks of cards
it would be much less apparent, maybe not even really noticeable. But
when your card backs are so stark even minor defects stand out like a
sore thumb.
It's an example of a practical issue arising from the graphical design.
When there's a lot less happening on the card, slight printing gotchas
will stand out far more. And if it's happening on the backs of cards
(which rely on looking identical to one another) then that can be a
problem - printing quality X that works fine for card design A might not
"work" for card design B.