Prussian blue in the context of "Ferrocyanide"

Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminium(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl₂O₄. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable, and has historically been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment "smalt".

In chemistry, cyanide (from Greek kyanos 'dark blue') is an inorganic chemical compound that contains a C≡N functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom.

Ionic cyanides contain the cyanide anion C≡N. This anion is extremely toxic and causes cyanide poisoning. Soluble cyanide salts such as sodium cyanide (NaCN), potassium cyanide (KCN) and tetraethylammonium cyanide ([(CH₃CH₂)₄N]CN) are also highly toxic.

The Great Wave off Kanagawa (Japanese: 神奈川沖浪裏, Hepburn: Kanagawa-oki Nami Ura; lit. 'Under the Wave off Kanagawa') is a woodblock print by the Japanese ukiyo-e artist Hokusai (1760–1849), created in late 1831 during the Edo period of Japanese history. The print depicts three boats moving through a storm-tossed sea, with a large, cresting wave forming a spiral in the centre over the boats and Mount Fuji in the background.

The print is Hokusai's best-known work and the first in his series Thirty-six Views of Mount Fuji, in which the use of Prussian blue revolutionised Japanese prints. The composition of The Great Wave is a synthesis of traditional Japanese prints and use of graphical perspective developed in Europe, and earned him immediate success in Japan and later in Europe, where Hokusai's art inspired works by the Impressionists. Several museums throughout the world hold copies of The Great Wave, many of which came from 19th-century private collections of Japanese prints. Only about 100 prints, in varying conditions, are thought to have survived into the 21st century.

A blue pencil, also known as a checking pencil, is a two-color pencil traditionally used by an editor to correct a written copy. The blue end is typically Prussian blue, and the red end is typically a warm vermilion red.They are most often half red and half blue, but some are 70% red and 30% blue. An editor-in-chief would use a blue colored pencil to make proofreading marks and final notes on manuscripts before sending it to be typeset and published. The pencils and their blue excisions became associated with the editing process and editorial oversight.

Since the introduction of desktop publishing, editing is typically done on computer files and without literal blue pencils. They continue to be used in the Japanese newspaper industry and elementary schools in parts of Europe. A different type of non-photo blue pencil is used by some comics artists for different purposes.

The term aizuri-e (Japanese: 藍摺絵 "blue printed picture") usually refers to Japanese woodblock prints that are printed entirely or predominantly in blue. When a second color is used, it is usually red. Even if only a single type of blue ink was used, variations in lightness and darkness (value) could be achieved by superimposing multiple printings of parts of the design or by the application of a gradation of ink to the wooden printing block (bokashi).

The development of aizuri-e was associated with the import of the pigment Prussian blue from Europe in the 1820s. This pigment had a number of advantages over the indigo or dayflower petal dyes that were previously used to create blue. It was more vivid, had greater tonal range and was more resistant to fading. It proved to be particularly effective in expressing depth and distance, and its popularity may have been a major factor in establishing pure landscape as a new genre of ukiyo-e print.

Marking blue or layout stain (sometimes called Dykem after trademark erosion of a popular brand, or Prussian blue after the blue pigment) is a dye used in metalworking to aid in marking out rough parts for further machining. It is used to stain or paint a metal object with a very thin layer of dye that can be scratched off using a scriber or other sharp instrument to reveal a bright, yet very narrow line in the metal underneath.

Ferric ammonium oxalate (also known as ammonium ferrioxalate or ammonium tris(oxalato)ferrate) is the ammonium salt of the anionic trisoxalato coordination complex of iron(III). It is a precursor to iron oxides, diverse coordination polymers, and Prussian Blue. The latter behavior is relevant to the manufacture of blueprint paper. Ferric ammonium oxalate has also been used in the synthesis of superconducting salts with bis(ethylene)dithiotetrathiafulvalene (BEDT-TTF), see Organic superconductor.