by Pesren
Great question John! They do not need to be diluted to use - washes & quick-paints are very "liquid" in texture already and ready to apply. For standard use and certainly for learning how they work, there's no need to dilute.However, there's still a potential reason to dilute them. If you dilute them, you'll reduce the intensity of the color going on the mini, so more of the primer's color will be exposed. So, if you prime white, and paint on a diluted red, you'll get a light/pink red effect. Green might come out more like Mint, Blue might come out Sky blue etc. Army Painter used to have a visual diagram on their pages for how much dilution (with "Medium") would effect the colors, but it looks like it was removed. Mixing washes/quick paints & diluting them can eventually give you new options for colors (again without costing much), but if you're starting out, definitely stick to just single, un-diluted colors until you get the hang of it.