I tried acid wash nails a while back. And I'm very pleased how it turned out actually! I certainly need to do this plenty more times with other colors.
How I did it: I started off by painting my nails with a black polish. I used "Black Creme" from Wet 'n' Wild. I did two coats and then top coated it. The top coat acts as a barrier for later when you start to create the design.
I then put on one coat of a teal polish. I used "Bella" from Essence. And then one coat of purple, "Gabriella" from Essence.
When all the layers are dry dip a tiny brush into pure acetone and drag it along the nail, making the acetone reveal the colors beneath. Be careful not to go too deep or your naked nail will show through. This is why you put a layer of top coat on top of the black.
Top coat to seal in the design and make it pop even more! What do you think? Click the "read more" tab for more pictures.