I collect rare & discontinued pigments and Genuine Manganese Blue (PB33) has been at the top of my “To Find” list. According to Handprint, this pigment was discontinued in the 1990s due to the tightening of environmental regulations. As such, all major watercolor manufacturers phased out production of the paint when their pigment supply ran out. Many manufacturers then started offering less-toxic formulations that approximate the original color.
After some hunting, I discovered a company on Etsy called Prodigal Sons Pigments that sells small, handmade batches of genuine manganese blue using PB33. It is pricey: $19 for a half pan and $30 for a full pan. They also sell pure pigment powder if you are interested in making your own paint.
Below are swatches of genuine manganese blue compared with some replacements, including Da Vinci’s version that is a combination of PB15 and PB33.
Without further ado, here are my observations…
The Prodigal Sons Pigments half pan of PB33 is loaded with pigment. Even a tiny dab on the end of your brush goes a long way. The color is what I would consider a perfect cyan and would likely be my go-to blue if it weren’t so precious (and toxic). It’s highly granulating, which is apparent in my swatches below (all done on Arches Cold Press).



This wet-on-wet test is a good demonstration of the color range. You can achieve a very light baby blue or the deep cyan of a vivid fall sky. This swatch showcases the beautiful granulating texture.

Below is a swatch of the Da Vinci Manganese Blue mixture that contains PB33 and PB15. It’s probable that the primary pigment is PB15 due to the mild granulation. It reminds me more of cerulean blue – both in color and granulation – than the genuine single-pigment Manganese Blue shown above.

This is a comparison of genuine Manganese Blue (top) and the Da Vinci Manganese Blue Mixture (bottom). The difference in the color and amount of granulation is quite apparent. While DaVinci’s is still a beautiful color, it is duller than the vivid genuine pigment and is far less granulating.

Many brands offer Manganese Blue substitutes, generally using PB15. Some brands add PW4 or PW6 to achieve a lighter cyan, but I didn’t swatch any of those. I stuck to single-pigment versions only.
The closest match to the genuine paint is Daniel Smith’s Manganese Blue Hue (PB15), although you can’t achieve the same color range as the original. However, it is the only version I tested that granulates. This paint has a permanent place in my palette because it is an excellent choice for a primary cyan.

Turner Watercolor also uses PB15, however it doesn’t granulate. It’s a very pretty color with a good range of light to dark. In that sense, I think it’s a good substitute if you prefer non-granulating paints.

The Winsor and Newton version also uses PB15 and it isn’t granulating. I found the color to be a bit weak and I couldn’t achieve a good range of light to dark. Out of the substitutes that I’ve tried, this is the least similar to the original.

Verdict: As much as I love the genuine Manganese Blue, I consider it a novelty because I use it so infrequently. Not only is it expensive, but it’s also highly toxic. The safer phthalo-based substitutes capture the essence of the original, especially the Daniel Smith version. If you aren’t a rare pigment hunter, PB33 isn’t a necessary addition to your palette.
Side note: I’m going to make the “discontinued and rare pigment” series a regular feature on my blog, so stay tuned for other interesting colors!






















