I’d appreciate your opinions on that. My friend thinks they’re tacky, but I don’t. I’m making a card for my graphic design business; it’s a dark gray with abstract lighting with white logos asymmetrically layered over it, with simple words in a light teal so it’s not monochromatic.

Not tacky if you’re able to convey your creative talent on your cards.
I don’t think it’s tacky…it’s a good representation of your business, which is known for it’s creativity and not adhering to ascribed ‘norms’. However, not seeing it for myself, I’m just guessing here, but I’d be concerned that it MIGHT be a little difficult to read, and that could turn out to be a subconscious turn-off for some people.