Heavy metal pigments used in silk printing

Each of the following articles is a collection of extracts from hard copy references held by the Sydney Powerhouse Museum Library, on silk printing in past decades. Collated and typed by Filip Szczepanski, LEAD Group volunteer, and located by Elizabeth O’Brien Manager, Global Lead Advice and Support Service (GLASS), Sydney, Australia with assistance from Powerhouse Museum Librarian Karen Johnson.

Many thanks to Karen for her encyclopaedic knowledge of the Powerhouse Museum library holdings.

Glossary of Graphic Arts Terms re: heavy metals (used in the Printing Ink Industry)

84-87

Barytes (see Blanc Fixe)

Natural barium sulphate used as an ink pigment and a white extender. It is considerably more abrasive and gritty than precipitated barium sulphate.

Blanc Fixe

Precipitated barium sulphate used as a semi-transparent extender in printing inks.

Cadmium Red

An inorganic red pigment which is resistant to light, heat and soap.

Cadmium Yellow

An inorganic yellow pigment which is resistant to light, heat and soap.

Chrome Green

A fairly light resistant opaque green pigment made by mixing freshly precipitated iron blue and chrome yellow.

Chrome Yellow

A light resistant opaque yellow pigment composed essentially of lead chromate.

Cobalt Drier

A material containing chemically combined cobalt used to accelerate oxidation and polymerization of an ink film.

Driers

Substances added to inks to hasten their drying. They consist mainly of metallic salts which exert a catalytic effect on the oxidation and polymerization of the oil vehicles employed.

Eosine

A fugitive organic dyestuff used to produce a brilliant red pigment for printing ink.

89-90

Inorganic Pigments

A class of pigments used in printing ink manufacture consisting of compounds of the various metals. Example: Chrome Yellow.

Iron Blue

A class of light fast, dark blue pigments, essentially ferric-ferrocyanide.

Iron Oxides

A series of compounds of oxygen and iron occurring naturally or manufactured, used as printing ink pigments. They vary in hue from yellow to brown, to red, to black. Some iron oxides have special properties that make them useful in magnetic printing inks.

Lead Driers

Chemical combinations of lead with various organic acids that are used as driers for printing ink.

Leafing

A phenomenon whereby metallic pigments form a layer parallel to the surface of the print thereby yielding a high metallic luster.

Linoleates

Generally the salts or soaps of linseed fatty acid. Cobalt, lead, and manganese linoleates are widely used as driers in printing inks.

Lithol Red

A relatively brilliant, moderately lightfast organic red pigment derived from a dyestuff by treatment with metallic salts. It varies from orange to deep maroon and is the most widely used red pigment.

Lithopone

Formerly a widely used white pigment consisting of varying percentages of barium sulfate and zinc sulfide. Rarely used in printing inks today. Largely replaced by titanium dioxide (which see).

Magnesium Carbonate

A transparent white extender used in printing inks, often called magnesia.

Manganese Driers

A material containing chemically combined manganese used to accelerate the oxidation and polymerization of an ink film.

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Metallic Inks

Inks composed of aluminum or bronze powders in varnish to produce gold or silver color effects.

Molybdate Orange

An inorganic pigment used to produce opaque orange inks and red inks. It consists of a mixture of lead chromate and lead molybdate.

Naphthenate Driers

Compounds of naphthenate acid with metals, usually lead, cobalt, or manganese used to accelerate the oxidation of the ink film.

Ochre

Naturally occurring yellow iron oxide pigment.

Permanent Violets

A light resistant, tungstated or molybdated methyl violet pigment used in printing inks.

Carbazole violet.

Phloxine

Blush red pigment used for process red inks. The hue is often referred to as magenta. The term phloxine is applied to the lead lake of eosine.

Prussian Blue

A red shade iron blue pigment.

Vermilion

A red mineral pigment consisting of a sulfide of mercury.

Zinc Oxide

An opaque inorganic white pigment used in inks.

Zinc Yellow

A yellow pigment consisting essentially of zinc chromate.