As a departure from my usual reviews, I will attempt for the first time to review a highlighter ink. There aren't many companies that make such inks, in my knowledge, apart from Pelikan with a single yellow ink and Noodler's which has a large variety of them.
For now I will review Noodler's Firefly Yellow, a yellow ink which is meant to be used to fill, well... highlighters. The concept here is that by refilling highlighter marker pens instead of throwing them away, it helps save not only money but also the environment, in the long run. As such, if you do a lot of highlighting and switch to these inks you'll be saving your wallet as well as the planet. That sounds great, so let's see how this ink performs. Is it a true replacement for the tried and true highlighter marker?
For my testing I used 2 pens: a J Herbin glass dip pen for the written text and a Pilot Parallel 6.0mm calligraphy pen. The Pilot Parallel is an amazing substitute for a highlighter marker. The tip never wears out and the edges of the line are very crisp. In addition, the 6mm nib is plenty wide.
From the start, Noodler's Firefly is a good choice because it keeps the same price as most of their other inks, namely $12.50 for a 3oz (89ml) bottle, which makes it $0.14 per milliliter, or $18.00 for a 4.5oz (133ml) bottle, which makes it $0.13 per milliliter. If you highlight a lot, the bigger bottle is obviously the better choice. Besides, it has a built-in eyedropper which might help you refill your marker. I did not buy a whole bottle, but just a sample.
Color and saturation
I will direct you straight to the sample I created on Rhodia 80g paper (shown at the end of this review). For comparison to Noodler's Firefly I used a regular Sharpie highlighter. A word of caution before I continue: the sample is definitely not color accurate. I tried my best at post-processing but I found it almost impossible to reproduce the color I see in real life.
Having said that, there is almost no difference between Noodler's Firefly and a regular highlighter. If anything, Firefly is more vibrant. The bright neon yellow is at least as powerful as the Sharpie. Placing the two side by side and now knowing which is which, you'd be hard pressed to tell the difference.
To test this ink I used it to highlight a few different types of text.
The first sample is written in Noodler's Heart of Darkness, which is a bulletproof (forgery resistant) and waterproof ink. Notice that there is some slight smearing thanks to my impatience. I should have waited longer for the ink to dry. Unfortunately even a bulletproof ink takes its time to dry completely on such a high quality paper as the Rhodia I used.
The second sample is written in Waterman Havana Brown, which is a standard, non-water resistant ink. There is some more smearing here but again, I should have let the ink dry longer.
The following 3 samples are written in pencil, Sharpie felt-tip and ballpoint pen. There's no smearing here, obviously.
All in all, the behavior of Firefly Yellow is as expected. For highlighting other inks I would advise you to let the ink dry thoroughly before highlighting.
There is no real shading to talk about here. If you look closely you will notice darker patches where the ink pooled a bit but that's not significant enough to consider it true shading. In fact, a regular marker would behave the same.
There is no feathering.
None, even on cheap photocopy paper. That's very good behavior, considering the wide swath applied by the Pilot Parallel.
Flow and lubrication
Firefly Yellow flowed really well in the Pilot Parallel.
Drying time wasn't amazing on Rhodia paper but it wasn't bad either. If you give it a few seconds before turning the page you should be ok. It obviously depends what pen you are using this ink in. I have a feeling that a proper marker pen with a felt tip would dry quicker. The Pilot Parallel does tend to produce wetter lines. On photocopy paper the drying time was even shorter.
Smearing when dry
Noodler's Firefly Yellow is not waterproof.
Noodler's Firefly Yellow is a great alternative to using disposable highlighter markers. Not only does it save the Earth a little but it can also help your wallet in the long run. It is a very well behaved ink which not only mimics a standard highlighter but even surpasses it a little in the vibrancy of its color. The only thing that keeps it from being perfect is the lack of water resistance but not everyone needs that feature in their highlighting ink. My only regret is that I don't use highlighter markers, or I would have bought a bottle of this ink without second thoughts.