Need SOLID opaque colors (no visible dots)

I know most printers print in dots, and that is normal. However, I need a printer that prints SOLID colors, with no dots visible to the naked eye. I want to print water-slide decals and use for nail art. The colors on the decals need to be opaque and solid. What type of printer do I need to purchase that can do this for me? And, is there a printer that can also do metallic colors? If there is not one that can do both, I'm more interested in a SOLID color print. Thank you in advance.