I have been using Pearl-ex pigment powder for ink for a few months now and I wanted to share my experience.
I got the idea here:
http://fpgeeks.com/forum/showthread.php/2259-Metallic-Dip-Pen-Ink-homemadeBasically you just mix 4 parts pigment with 1 part gum arabic (I've been using powdered but liquid gum arabic should work just as well) and enough water to get an inky consistency. I LOVE this as ink. It is smooth, opaque, hairlines are good, and the colors are just gorgeous! So here is what I've tried so far.
Jacquard Pearl-exAztec GoldA darker gold, kind of orange-ish. Very rich smooth and opaque
Brilliant GoldA Much lighter more yellow gold than Aztec. A bit too light for white paper in my opinion but absolutely stunning on black. Also smooth flowing and opaque
Sparkle GoldApparently this is the same color as brilliant gold except a larger particle size. I did not know that when I bought it. It is a lovely color and true to it's name it is sparkly...but the the larger particle size makes it a pain to work with. I don't recommend using it with pointed pen.
Antique SilverThis is a nice pewter color. I love it. It is understated, not too flashy, but a very interesting departure from say black ink. Very good flow and opacity. Works beautifully with both light and dark papers. See a recent instagram post (@elsabduncan) to see it on a black envelope.
Pearl WhiteI don't love this one. The particle size is a bit too large which makes for dry looking upstrokes.
You can get this product at most craft stores, although at Michael's I've only ever seen it in 12 packs (assorted colors). I bought mine at Joann online. Here is the link.
http://www.joann.com/jacquard-pearl-ex-powdered-pigments-3gr/2054997.html?mkwid=YTvUh3AK|
Dick Blick online store also has huge selection of colors.
Downsides:
Pigments are heavy and must be constantly stirred....like seriously, constantly
Not remotely waterproof or resistant (which makes for really easy cleanup though)
I have tried Ranger Perfect Pearls...basically the same kind of thing, different brand. Their pigments are not as fine and I think writing with them may have ruined my nibs. I think Pearl-ex is a much better choice.
Compared to Dr Martin's Copperplate Gold, the brilliant gold looks very similar on black paper, but Dr Martin's is much more brown looking on light paper.
Here are some photos. Metallics are soooo challenging to photograph in their full glory, but I did my best.
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New reviews:
I have since bought the Silver, Emerald, Copper, and Pink Gold pigments and here are my thoughts on those:
Silver: Super smooth. Not heaps different from Antique Silver which I already had, but a bit lighter. Shows up well enough on white and very well on black.
Emerald: Pretty smooth, nice shade of emerald. Shows up equally well on black and white papers.
Copper: A really pretty sparkly color, but the particle size is just too large. Nearly every upstroke is dry all of the time. I don't recommend for pointed pen.
Pink Gold: Writes smooth looks very different on white paper than on black. It is mostly a pink pigment which reflects gold, so it looks a lot more pink on light paper and a lot more gold on dark paper. Joi posted a picture of it here
http://theflourishforum.com/forum/index.php?topic=1471.15