Prussian Blue, Milori blue

PB27

Alternate Names

Antwerp Blue

Berlin blue

Paris Blue

Pigment Description

Prussian Blue or Milori Blue. A color with a strange backstory, as its discovery involved blood. This is a moody, dark, transparent indigo that is great for marine landscapes as well as any darkened middle to low chroma color in the blues.

As a strange quirk this color can show bronzing where it develops a sheen in masstone.

Unfortunately its lightfastness isn't what was once thought, as Prussian Blue is fairly sensitive to the mixing white involved. It's interesting that this was ever listed as ASTM I as certain pigment suppliers now list its performance in tints to be quite low (as low as blue wool scale 2)!

This pigment requires a fairly high amount of oil and yet it is a fast drier.

Prussian Blue has a lot of related color names which fly under the flag of PB27 such as Antwerp Blue and several others. For toxicity please consult Monona Rossol's work, as there are some unexpected hazards.

Resources

PB27 pigment data from David G. Myers, The Color of Art Pigment Database, Artiscreation.com

Church, A. H. The Chemistry of Paints and Painting. London : Seeley, Service, 1915. Internet Archive, Web. Accessed June 2025. https://archive.org/details/chemistryofpaint00churuoft

Field, George. Field's Chromatography : a treatise on colours and pigments for the use of artists. London : Winsor and Newton, 1885. Internet Archive, Web. Accessed June 2025. https://archive.org/details/Fieldquotschrom00Fiel

Gettens, Rutherford J.. Painting materials : a short encyclopaedia. New York : Dover Publications, 1966. Internet Archive, Web. Accessed June 2025. https://archive.org/details/paintingmaterial0000gett Feller, Robert L, ed.. Artists' pigments : a handbook of their history and characteristics. Washington, DC : National Gallery of Art, 1986. Internet Archive, Web. Accessed June 2025. https://archive.org/details/artistspigmentsh0000unse

Information about PB27 from Bruce MacEvoy, Handprint Guide to Watercolors, General information about this class of pigments from Handprint

CAMEO Materials Database: Conservation & Art Materials Encyclopedia Online, Museum of Fine Arts Boston. (Accessed June 2025). Prussian Blue https://cameo.mfa.org/wiki/Prussian_blue. Museum of Fine Arts Boston,

Rossol, Monona. The Artist's Complete Health and Safety Guide. New York, NY : Allworth Press, 2001. The book is rather dated, updated information is available from her website

Mayer, Ralph. The Artist's Handbook of Materials and Techniques, 5th ed., New York, NY, Penguin Group, 1991. https://amzn.to/44OzBN9

Stats

Lightfastness

Variable

Golden’s Lightfastness Testing in oils showed variability for PB27 due to the choice of mixing white. The lightfastness tanks in Flake White. Their main table of results (Table 3) it shows mostly ASTM I and II behavior, however results were not included there for Flake White and Zinc White (for Flake White performance see Table 9). The lightfastness slid to ASTM II in Titanium White in Linseed oil. It also showed some potential sensitivity to humidity (Florida testing) where it performed poorly, and also showed significant fading in QUV testing.

Transparency

Transparent

Toxicity

Thought to be in the category of Lower Concern but may have some hazards

Avoid acid, high heat, and strong UV. Please see Monona Rossol's work for more information. Treat all pigments and paints with studio safety protocols.

Dry Time

Most PB27 paints average around 2 days

Oil Content

Varies. Some sources say high, but the comparison by volume can actually be low. Mayer assigned Prussian Blue high oil volume, with a score of 96.

Sources vary on this one. Some list medium-high to very-high while Williamsburg listed it as very low on a comparison article. More information available here. When made into a paint it may have slightly higher requirements, as we have heard that pure pigment and oil is less than ideal for Prussian Blue (see the comments on the linked article for more).

Chemical Name

Synthetic Ferric ferrocyanide, ferriammonium ferrocyanide, alkali ferric ferroyanide

Dry Pigments listing PB27

DISCLAIMER: Please note that we are not experts in health and safety and we are not toxicologists, please consult the proper experts. We are not liable for any issues that may arise from the use of our website or its contents. The information contained in this site is provided without warranty or guarantee of any kind. We do not necessarily endorse any other website that are linked from our site. For any important pigment specs, please reference the manufacturer details. If you discover errors or omissions, please reach out through our contact form. Thank you.