Weld or Reseda has been used as a dye for millenia, from the robes of the Vestal Virgins in Rome to ancient Egyptian wool tapestries, interestingly until the 19th Century it was the most used yellow dye. Like most 'dyes' used as oil paint pigments here it is prepared as a 'lake' to help stabilize it.
In masstone it is darkish, yellow brown and feels quite unique not really having the 'bulk' of a average oil paint. It is very transparent and when thinly used the yellow aspect really comes out, as a mid value, warmish yellow.
As expected it has pretty low tinting power, however there are still a range of gentle yellow tints which can be produced, when Titanium white is added it also cools it quite dramatically. This is a subtle paint.
To me although from a different plant it feels quite similar in handling and colour to Stil de Grain (made from Buckthorn berries) and it is the same chemical compound in both plants which produces the yellow hue. The Weld plant is pictured opposite.
This is a special paint and unique to Wallace Seymour, I see it working best for glazing or for the painter who is working with historic pigments or a restorer or someone to whom the natural/ancient/plant based pigments are of interest.
Pigment - Weld/Reseda
Vehicle - Linseed Oil
Tint Power - Low
Opacity - Transparency