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    Top Pigment

    Viridian

    PG18

    Alternate Names

    Hydrated Chromium Oxide Green

    Transparent Chromium Oxide

    hydrous chromium sesquioxide

    Guignet’s Green

    Pigment Description

    An enchanting deep Emerald green with transparency. This lovely color makes excellent glazes as well as interesting mixes which can actually go quite bluish in tints. Debate rages as to whether phthalo green (a similar color) can replace the historical viridian, and we have found the answer to be not completely.

    Pigment image

    Old Holland Viridian Deep oil paint, made with PG18

    Some painters prefer Viridian to Phthalo Green PG7 as it is gentler in many respects. Though both are transparent the two have slightly different qualities. When mixing colors that are just shy of highest chroma (which happens a lot in realistic painting) Viridian is a much more straightforward green to use. Phthalo can be used, but may take another pigment or two to counterbalance it in order to achieve a similar effect. Viridian is often paired with cadmium in cadmium green mixes, probably due to the copper in Phthalo.

    A daub of oil paint made with genuine viridian

    Old Holland Viridian Green Deep, pigment PG18

    One interesting quirk we've found is that some brands of viridian oil paint actually seem to shift in appearance when dried. Out of the tube they may look almost indistinguishable from phthalo green, however after drying the two may appear different.

    A stroke of Viridian oil paint

    Michael Harding Viridian, made with PG18

    Viridian has a very high oil content when made into paint, which may be important to keep in mind if painting in layers.

    An impasto swoosh of viridian oil paint

    Williamsburg Viridian, made with PG18

    In the Artist's Guide to Health and Safety Monona Rossol has information on working with pigments containing Chrome, however in her latest work she distinguishes that this color has Chrome III.

    A jar of Viridian Dry pigment, PG18

    Vintage Bocour Dry Pigment, Viridian Green PG18

    On a rather alarming note, we've noticed that Viridian pigment is becoming harder to find in paints. Perhaps due to its cost, in some corporate paint brands, such as Winsor and Newton, Viridian has become rare. That's too bad, as it is a lovely pigment with charms all its own.

    A small bottle of Viridian dry pigment

    Kremer Pigments Viridian Green, PG18

    Resources

    PG18 pigment data from David G. Myers, The Color of Art Pigment Database, Artiscreation.com,

    Spurgeon, Tad. Living Craft: A Painter's Process. Mt. Airy, Philadelphia, PA: Zoetrope, 2018. Newer version available here: https://www.thomaskitts.com/page/36804/tad-spurgeons-living-craft,

    Information about PG18 from Bruce MacEvoy, Handprint Guide to Watercolors, General information about this class of pigments from Handprint,

    Douma, Michael (Accessed June 2026). Viridian https://www.webexhibits.org/pigments/indiv/history/viridian.html. Web Exhibits, Pigments through the Ages,

    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.

    Stats

    Lightfastness

    Excellent

    In Golden’s lightfastness testing in oils, this pigment performed well. There were a few instances where it slid to ASTM II (very good) such as in Flake White in linseed oil, as well as in pure zinc white. Overall it performed at ASTM I (excellent).

    Transparency

    Transparent

    Toxicity

    Potential Hazard, Use more caution

    Artiscreation assigns a rating between lower concern and possibly hazardous (A/B rating). In the Artist's Guide to Health and Safety Monona Rossol has information on working with pigments containing Chrome, however in her latest work she distinguishes that this color has Chrome III. The NPIRI mentions Boron Oxide as well.

    Dry Time

    Slow, may contain driers

    Spurgeon writes this is, "not the best drier."\Some paintmakers add driers and reduce the dry time to 1-2 days. Driers can introduce their own problems later down the road.

    Oil Content

    Varies from Medium to Very High

    Some sources say very high. Mayer assigned it to the Very High category with a score of 233 (one of the highest). By weight, Artiscreation lists a range of approximately 90g/100g of oil, but your pigment may have different requirements. Weight ratios are a more dialed-in way to go about paintmaking, but volume ratios are more helpful for visualizing relative amounts, since pigments vary in weight.

    Chemical Name

    Hydrated chromium(III) oxide

    with PG18 (Viridian)
    No single-pigment Oil found with PG18

    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.

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