Michael Harding Red Umber - A synthetic iron oxide. Michael Harding decided to make this variant shade of Burnt Umber as a result of his observations of 16 -17th century paintings which suggested that this pigment had lighter and redder characteristics than those it assumed when manufactured in held in animal bladders. Raw Umber is calcinated to make the pigment, and the extent of Manganese Dioxide mixed with the Iron Oxide determines the range of undertones; this formulation is much warmer than is usual.
| Color Index | PBr6 |
| Drying Speed | Very Fast |
| Transparency | Semi-Transparent |
| Lightfastness | Excellent |
| Oil Content | Average |
| Tint Power | Average |
| Toxicity | Non-Toxic |
| ASTM D-4236 | ✓ |