Interesting one! I expected this to have a real reddish glow like a Transparent Oxide however it doesn't and then I remembered it is an umber so ultimately we are dealing with greys and browns and in that respect it is indeed a warm umber. I seriously hope that last sentence makes some sense to someone, somewhere!
Tinted with white it produces purplish greys. Smoothly ground in linseed oil.
Michael Harding -
"I decided to make this variant shade of Burnt Umber as a result of my observation of 16th-17th Century Painting which suggested this pigment had lighter and redder characteristics than those it assumed when manufactured in bladders and later tubes, began a century later. Raw Umber is calcined to make this pigment, and the extent of Manganese Oxides in relation to the Iron Oxides determines the range of undertones here much warmer than usual.
Pigment - PBr7
Vehicle - Linseed Oil
Opacity - Transparent
Tint Power - Low