Chromium-lead compounds

Yellow chromiums belong to the bright dyes with a lemon hue.
Orange chromiums are similar in color to orangish cadmiums.
Red chromes are not inferior in brightness to cinnabar.
Chromes came into use in the late 18th century.

Yellow chromiums - chromium-lead salt. Lead chromate

Durability depends on the color scale: bright chromates - less durable, red chromates - more durable.
As a lead dye, it cannot be combined with sulfur dyes.
Poisonous, sensitive to hydrogen sulfide and alkali (not used in alkaline welds).
They turn green on light within a year (especially grated on oil).
Orangish and red chromiums are more resistant to light.
Yellow and orangish chromes are used in all techniques except fresco and stereochromism.
Red chrome has a crystalline structure and cannot be strongly rubbed off. Therefore, it is not used in oil technique, but rather in tempera.
Chromes hide well. They dry quickly in oil and take it from 35 to 40%.
Recognition:
Yellow chromes dissolve in dilute hydrochloric acid to form a yellow solution and a precipitate (yellow) that dissolves either in water or when heated.
Reds dissolve when heated in hydrochloric or nitric acid, producing an intensely yellow solution.

Neapolitan yellow (lead antimonate)

Known in Italy as early as the 15th century (giallolino).
It is mined near Vesuvius (volcanic origin).
Resistant to light and alkalis, it dries well.
Light yellow in color. Poisonous. In oil it hides well, taking it from 15 to 20%. Permanent in all connections (only metallic iron, lead or zinc acts on it).
Used in all techniques. In watercolor it is not resistant to sulfur compounds.
Recognition:
In acid solutions it does not dissolve but decomposes without coloring the solution (unlike yellow chromium). In alkalis and from temperature it does not change.

Cassel yellow (various compounds of chlorinated lead with lead oxide).

Light yellow to brown color. Known since 1809. Impermanent, especially in combinations with copper dyes. Used in oil, tempera and watercolor.
In oil it dries well, takes it 15%.
Recognition:
When heated in nitric acid, it dissolves to give a colorless solution.