“Basic lead carbonate. A warm, buttery white with a beautiful sheen like pearls. Very flexible. Least prone to cracking when used thickly.” “SF Flake White is similar in working properties to its linseed oil-based counterpart. SF Flake is slightly whiter from the tube and mixes cooler, less yellow colors than linseed oil-based Flake. As mentioned above, colors made with safflower oil should yellow less over the long-term, and are better used thinly and in the upper layers of a work. To build up a painting with many layers, we recommend starting with linseed oil – based colors for a more durable base, and then transition to SF colors in the upper layers to have less yellowing whites and color mixtures.” Also this cited elsewhere, “Note on lead toxicity – lead can enter body through ingestion, inhalation of pigment particles and through broken skin.  This product is safe when used as intended by professional artists. Paintings containing Flake White should not be sanded.” -Just Paint 2020 -Williamsburg