Zinc oxide is white at regular temperatures and yellow when heated. It can be prepared in a broad range of particle sizes, from macro conglomerates of several tens of microns, to colloidal dimensions, up to ultra microscopic nano particles. It is most often marketed in the form of a very fine powder.

Zinc oxide is produced commercially in either of two methods:

• The indirect process (the French process), in which zinc metal or metallic residues are used.
• The direct process (the American process), in which zinc ores, zinc ashes and/or other materials are used.