Choosing the Correct Black \ White
Choosing blacks
While the hues of the three blacks are similar, the character of each pigment is different. The different qualities of each pigment determine their suitability for different applications. Jetness is the term used to describe how black a black is.
Sheen and jetness
Sheen affects our perception of jetness. Carbon black looks the blackest because it is naturally the shiniest pigment – but if all the blacks are glazed with clear acrylic medium to bring them to an equal shine, the most jet is bone, followed by mars, carbon being the least jet. Bone black has a matt sheen and is useful as a ground, or in underpainting because its rough surface makes a good bond with subsequent layers of paint.
Tint Strength
The comparative tint strengths of the blacks are the reverse of the order of their jetness. To create the same tone of grey, less carbon black needs to be added than bone black. Carbon black is good for glazing because its high tint strength means that an even, dark tone can be produced in highly diluted mixes. Bone black with its low tint strength is useful in precise work for desaturating colours in fine increments. Because of its low tint strength it appears to be less opaque than the other two blacks. Mars black, which has both medium tint strength and medium sheen, (neither matt nor gloss), is a good all-round black suitable for most applications.
Zinc White vs. Titanium White
Both titanium and zinc white have excellent lightfastness ratings. Titanium white has much greater hiding power than zinc white. As well as being more opaque, titanium white has a higher tint strength than zinc white, which means that zinc white is more convenient to work with when doing precise work, as it is easier to lighten colours in smaller increments. Because it is semitransparent, zinc white is more appropriate than titanium when using glazing techniques or in watercolour style washes. Tints made with titanium white tend to have a more subdued, “pastel” quality than those made with zinc white which retain a fuller saturation of colour.
