Natural Black Oxide is a natural black earth from slate deposits in the vicinity of Rome that is a semi-opaque black, and is absolutely permanent. It is comparatively neutral in undertone, wets easily, and is non-greasy, when compared to carbon blacks.
Rublev Colours Roman Black Watercolor
Note: Colors swatches are shown in mass tone, at top, mixed with an equal amount of water and brushed out toward the bottom. All pictures of color swatches in this web site are only approximations of the actual color of the watercolor paint. We have taken every care to match the color in these pictures on calibrated color monitors to the actual color. However, because of the wide variance in color monitors the results you get may vary.
| Pigment Names | |
| Common Names: | English: black oxide French: oxyde noir German: Oxid Schwarzes Italian: ossido nero Portuguese: �xido preto Spanish: �xido negro |
| Alternate Names: | English: black iron oxide, iron oxide French: fer oxyd�, naturelle noir Indien Mars black is the name given to the artificial substitute of natural black oxide. |
| Color Information | |
| Single Pigment: | Roman Black |
| Binder: | Gum Arabic |
| Pigment Information | |
| Color: | Black |
| Colour Index: | Pigment Black 11 (77499) |
| Chemical Name: | Iron oxide produced from magnetite ore |
| Chemical Formula: | Fe3O4 |
| Properties | |
| ASTM Lightfastness: | I |
| Opacity: | Semi-Opaque |
| Tinting Strength: | Medium |
| Staining: | Low |
| Granulating: | High |
Note: Some separation of pigment and medium may occur in Rublev Colours Watercolors and is a natural process when no stabilizers are added to paint to prevent this from occurring.