What is actually in the tube, why it dries slowly, and how Rembrandt used bone black to make a robe darker than the shadows behind it.

Every earth red on your palette leans warm. Except one - and that one is the reason a cheek can actually turn away from the light.

Every painting before the 20th century was built on it. Here is what it actually does, why a few painters still use it, and what to watch for if you open that tin.

Skin shadows are not gray. They are red - and this ancient pigment is how painters have known that for 25,000 years.

Why portrait painters use alizarin crimson in exactly the application where it fades fastest - and what the permanent swap actually means.

PV15 is not a separate mineral - it is ultramarine blue that has been baked until the chemistry flips. Here is what that means for how you mix it.

Most red ochre is opaque. One version is not - and it changes everything about how you glaze warm darks.

Why the most expensive pigment in history still earns its place on your palette, and the three mixes that prove it.

The most powerful yellow on your palette is also the easiest to misuse - here is what it actually does in oil, and the three mixes that make skin glow.

PO20 is the pigment hiding in your flesh tones, your shadow passages, and your portrait's most convincing warmth - here is what it actually does in oil.

Why soft light on skin is a warm cream - not white - and how a 3,500-year-old pigment does that job better than anything else on your palette.

Four blues walk into a flesh mix. Only one comes out clean - and the reason explains half of portrait painting.

Terre verte, the verdaccio tradition, and the three mixes that keep flesh from going sunburnt.

You don't need a doctor's anatomy to paint - you need the artist's. Here's why it sets you free.

If there is such a thing called a "normal way of working" then this is the process of initial drawing of the portrait