I have used a variety of hobby paints throughout the years, Citadel, Army Painter, Formula P3 and others. I like experimenting with them, and find that such variety can help, especially in terms of highlighting and detail work.
Vallejo paints, especially their Game Colour line, have been the paints that I have returned to using time and time again. Each paint line has different thicknesses, pigments, flow, and with Vallejo, I find it suits my style and needs, though, of course, your style and needs will differ. However, I would easily recommend Vallejo as a starting system, from which one can later branch out into other paint brands if one feels they need more of some quality from a paint.
The Vallejo Face and Skin Tone Set, are from their Model Colour line of paints. This has been my go to for skin colours of late, as the many shades in Model Colour allow greater immediate variety as opposed to Game Colour’s selection. Now, one could use only Game Colour, and with some blending, get a variety of skin tones in that manner. However, if I use up that blend, even with my note taking on said blends, sometimes the mix is just a tad off, making further work difficult. The Face and Skin Tone Set has a variety right away, which allows for painting right away instead of mixing and note taking.
While I stated my preference for Vallejo Game Colour, I easily recommend their Model Colour Face and Skin Tone Set. It expands and compliments the skin colour options in the Game Colour line, and being that both are Vallejo products, these can be blended with ease as you require.
