This is the lighter (tonally) version of Lead Tin yellow, it is high in value. The masstone hue is a light lemon yellow and although it leans to green it is a very slim leaning. Such is the high value, tints are almost irrelevant, it does maintain it's chroma when white is added however the range of tints is quite small. It has a lot of body.
I see this working well to lift the value of mixes without using white and cooling them too much, it is also going to work well on a portrait palette. Apparently though I haven't tried this it makes very lively, vibrant greens when mixed with blue. It has very good covering power, very opaque.
A very important paint historically, found in frescoes from the 13th Century and then used widely throughout the Renaissance, to such a point it became known as the 'yellow of the old masters'.
Technical Overview
Pigment - Lead-Tin Oxide (Lead Stannate)
Opacity - Opaque
Tinting Strength - Medium
Drying Time - Fast