Neon Fluorescent UV Blacklight Reactive Glow Paints! Fugitive and Rare Lightfast Minerals with Fluorescent Properties in Watercolors.
In any type of paint (such as watercolor, gouache or acrylic) black light reactive fluorescent colors are always fugitive. They fade over time when exposed to sunlight and the lack of lightfastness is often severe enough that even paintings hung on a wall indoors can start to fade from the UV light of a nearby window. I say "almost" always fade because it should be noted that sometimes they are mixed with stable pigments in certain paints, which results in a color that does not appear to fade in normal light, but does stop "glowing" after too much sun exposure. By "glowing" I mean that these fluoresce, appearing unusually bright under black light. This means that some colors can be used for brief special effects under black light, as well as have the benefit of long term display stability in normal lighting.
These special effects paints are primarily in demand by artists using them for artwork to scan/print reproduce, personal work, party events with black lights (where the paints will appear to "glow in the dark" due to their reflective properties) etc. The term "glow in the dark" should only be used here in regards to appearance, as these are not the same as phosphorescent pigments that are charged by sunlight and glow in the dark without the continued presence of a UV light (purple/black light). Most often fluorescent watercolor paints are labeled as "neon" but sometimes also "Opera", "Brilliant", "Bright" or "Vivid" in their color names.
You can test the paints you own for fluorescent dyes by using a blacklight flashlight, light bulb or LED strip such as these:
Some popular colors, like Opera Pink in watercolors, are made by combining a stable lightfast pigment (Magenta PR122) with a brightly colored dye (typically BV10 or BR1, a thin particle fluorescent dye suspended in the binder/coating the more substantial particle pigment). These colors are usually chemically man made to be abnormally vibrant to the eye, much more than natural mineral pigments.
While Neon colors look intensely bright (like a yellow highlighter marker) and usually contain fugitive dyes, there are some rare fluorescent (black light reflective) paints made with lightfast pigments.
Rare natural fluorescent mineral called BLUE APATITE by Daniel Smith:
This rock contains small amounts of naturally fluorescent minerals, such as fluorite which has a gentle deep blue-violet glow under black light. The underlying blue color that makes up the rest of Blue Apatite is lightfast, meaning the dark blue color will not fade to the naked eye in normal light. If left near a sunny window, only the black light effect will fade over time. This is not as bright under black light as Manganese Blue Hue.
MANGANESE BLUE HUE by Daniel Smith. A unique coarse version of PB15. Slightly less finely ground than normal Phthalo Blue, resulting in an easy-lifting/non-staining and granulating color that closely resembles the discontinued pigment PB33 Manganese Blue Genuine.
This color appears to include an optical brightener (whitening / brightening agent with fluorescent properties). Note that PB15, 15:3 and other Phthalo Blues made by other watercolor paint companies do NOT contain this fluorescent element. This chemical addition is only available through Daniel Smith/their particular pigment manufacturer. I have seen the use of cyanine dyes in "neon blue" acrylic paints (see golden fluid acrylic or liquitex products) but the underlying blue dye colorant also fades in those (unlike this clear/colorless additive in Daniel Smith that fades independently of the lightfast blue PB15 pigment).
This has the same bright blue-glow under black light as "invisible ink" and other optical brightener/whitening agents in acrylic fx paints, which I talk about further down the page. Manganese Blue Hue has a useful underlying sky blue color. Having this being available in watercolor form instead of an ink bottle can be more conveniently used, such as allowing it to dry in an empty watercolor paint pan to place in a travel palette.
Manganese Blue Hue from Daniel Smith has a stable blue base color from Phthalo Blue PB15 - but this appears to be a unusually coarse, textural/granulating version. The fluorescent glow under black light is due to an added optical brightener. A unique color, likely most appreciated by those who have had the opportunity to try the original Manganese Blue Genuine PB33 (discontinued around 2016-2017). PB33 was very toxic and stopped being mass manufactured as a pigment, causing paint brands like D.Smith, Old Holland and Lukas to no longer sell it. This caused a lot of sadness in the art community, as PB33 was considered a near perfect primary cyan blue with intense granulation. It was much less opaque than Cobalt Teal / Turquoise or Cerulean. This hue from Daniel Smith is the closest match to PB33 I've ever seen.
Daniel Smith's Manganese Blue Hue is not intended to be a UV black light special effect paint. This aspect of the paint was not mentioned. While fluorescent effects (refracting UV-A under black light) are always fugitive, you won't be able to see that issue without a black light. It will stop "glowing" from UV after too much sun exposure (as seen in my lightfast tests). The underlying blue (PB15) is lightfast, this blue color will not change or be a problem for most artists. In my secondary lightfast tests including heavily diluted paint, even light washes of this color were completely stable in visible daylight for over 6 months (despite receiving direct daily sunlight) - a good sign! It has almost undetectable hue dulling/shift after 1 year of sunlight, on par with it's LFII rating.
Manganese Blue Hue has a very strong, bright blue glow under black light.
Manganese Blue Hue is also used in Daniel Smith's Lunar Blue where it was mixed with PBk11 Lunar Black. If you prefer the black-speckles or darker color of this paint in always-visible daylight, it also glows bright blue just like MBH under black light.
The following paints are only moderately lightfast (in normal light) fluorescent pigments. They will fade over time, visibly even in normal daylight, in addition to losing their fluorescence under black light if exposed to too many months of repeat sunlight exposure:
While fugitive in comparison to the most stable lightfast pigments, this color is less prone to fading when used full strength. The masstone tends to have minor fading only when exposed to 3 or more months of daily direct sunlight. When used diluted, pale washes of this color can fade within weeks. This is better light resistance than some dye based "neon" colors on the market. However, this color does not appear "neon" in normal day light or indoor light bulbs, rather only showing its fluorescent light reflecting glow when under UV black lights:
Fugitive dyes: Rhodamine dyes are common in colors called "opera" or "neon" pink. They can also be present in any watercolor or gouache paint listed as "brilliant" as well as many colors in "designer gouache" (winsor and newton, daler rowney, even schmincke's designer gouache contains dyes). This type of dye normally glows bright pink or violet under uv light and is sometimes listed as a pigment (bound with salt) in colors like bengal/rose tyrian in gouache.
OPERA PINK (mixture, typically fluorescent dye coated PR122).
Most watercolor brands offer at least one fluorescent pink, often called OPERA PINK. White Nights calls theirs Neon Pink and another affordable entry-level pro-grade watercolor brand is ShinHan. On the more expensive end, the top pro-grade brands like Daniel Smith, Winsor and Newton and Schmincke all also offer a version.
Variety of colors - NEON watercolors:
Paul Rubens makes an affordable neon set that is bright both in normal light and is blindingly bright in UV black light. Great for kids rooms with art of glowing insects or bioluminescent sea life. These perform just like professional grade watercolors in flow, pigment load, re-wettability etc. Note that the Ultramarine Blue in this set does not glow, but does offer an interesting granulating color to mix the fluorescent yellow, orange, pink and green with. I recommend finding white or blue glowing paints either in Daniel Smith's option or handmade watercolors (etsy) which use the pigment powders below.
Pigment powders that are "neon" are often made from thin particulate dyes adhered to a salt carrier, sometimes called a "lake pigment". They can also be a coated secondary pigment such as PW6 Titanium White, which can be mixed with gum arabic or clear acrylic medium for paint making:
Invisible Ink - Blue Ghost Ink by Noodler's: a great way to add an optical brightener to ink and watercolor art. This thin, clear fluid, will look invisible in daylight but glow bright blue under black light.
As an alternative to watercolor paints, this fountain pen ink goes on clear and can be used to add glow-effects over otherwise UV stable paintings. It's also a way to make invisible art on the wall that only comes to life when you turn on the UV black lights. It contains fluorescent dye suspended in water and preservatives, instead of being infused with pigments to make thick paints like the other options on this page. This smooth flowing liquid can be used with dip pens, fountain pens or a paint brush. The bright blue glow will remain viable for many months, especially if not hung on a wall that receives direct beams of light from a nearby window.
There are heavier, substantial paints that are also clear or white with this blue glow. These acrylics are made from optical brighteners as well:
Modern Masters invisible blue (made by Rustoleum) can be purchased at Blick here.
UV FX by Tri-Art is a clear "matte medium" (essentially a clear acrylic paint that can be used as a sealer that glows bright blue under black light), also available at Blick here.
Looking for where to buy watercolors and other paint? I purchase my art supplies at Amazon, Blick or Jacksons. I use affiliate links. As an Amazon associate, I earn from qualifying purchases. Thank you :)
Both Blick USA and Jacksons (Worldwide) carry a variety of paint manufacturers, such as Rembrandt, Daniel Smith, Schmincke, Sennelier, Mission Gold etc. Though there are several harder to find brands that are store specific - Blick carries Da Vinci and Jackson's has White Nights and ShinHan.
If you'd like to see more, check out the pigment database where I compare each color to the same pigment from other brands. The lightfast testing and brand overview page takes an in-depth look at each brand, one at a time.