Baking powder (makeup)

In makeup vocabulary, baking powder is shorthand for the finely milled loose setting powder used in the baking technique: pressed on in a thick layer, left to sit, then dusted away. Some brands sell a product under that exact name, but functionally it is a loose powder — usually translucent or lightly tinted, built on ingredients such as starches, silica, talc or mica.

A good one is milled fine enough to blur rather than sit visibly on the surface, and it is often chosen by how it behaves on camera: powders containing certain light-reflecting minerals can cause white flashback in flash photography, which matters if you are photographed often.

Worth stating plainly, because the names collide: culinary baking powder and bicarbonate of soda are a different thing entirely. They are alkaline, well above skin's natural pH, and DIY scrubs or masks built on them can disturb the acid mantle and leave skin tight, irritated and more reactive afterwards. Use cosmetic powder for cosmetic purposes, and patch test new products as usual.