I think that "someone" you should know is JPL, on KZread 😉

Definitely JPL!

Just use blood. Nice color, and plentiful!

Given the bottles of inks I have, the more useful question would be “can I use ink as food coloring?”

I've used food coloring in my dippers and in my cheap Chinese pens for more than a year with great success. I've even concocted a beautiful aqua shade and a bronze that mimics Diamine's Ancient Copper.

JPL intensifies

Just fyi the certain someone probably is young and handsome 😉 JPL, Australian pen/ink You Tuber.

A few minutes ago i watched a video someone food coloring as ink for one year and no damage happened to the fountain pen he used...

I've used it for months and it works great, feathers a bit more, but its not so bad. still totally legible.

One of my favorite brand of inks is one of the cheapest too. Their red is a rich, blood-red. Their black is solid black. Never had a single issue with Sheaffer. Want another great value? Head on over to Goulet Pens. Monteverde 90ml bottles. Numerous colors. $15.oo each. Most folks don't realize just how much writing you need to do to empty a 90ml bottle of ink. That's almost an insane amount of ink. There's just no need to go ultra cheap. Especially on a particularly valuable pen. Why risk it?

JPL rocks!

i found with my little bit of experimentation that i use yellow liquid food color and noodler's blue ghost to give it a 1:1 ratio of ink to food color to make up for the lubrication and it works out rather well at least with yellow food color i used monteverde valentine red and yellow food color to make a apachi sunset replacement and monteverde caribbean blue and yellow food color to make a cool green for easter and ratios may very you have to do a fair bit of experimentation with syringes and a twisted unraveled paper clip and paper to get your desired color but once you do wow there are a plethora of colors out there that you can use

Considering that many fountain pen inks are also not lightfast, I see no issue with the food coloring. My favorite fountain pen is a cheap one anyway so I've got nothing to lose. My Preppy has been working perfectly fine with food coloring.

I tried black food coloring in a cheap pen. It takes a long time to dry and doesn’t really look good.

Using food colouring in fountain pens as is is not the best experience. But you can make you own ink with food grade water soluble dyes. You will need synthetic or natural polymer resins, biocides, surfactants, humectants, stabilizers, pH modifiers and anti-foaming agents. The good thing is - you can get all the components in stores, it only requires basic chemistry knowledge, can be done in your kitchen and is fun. The downside: it's a bit time consuming, gets hands funny coloured, individual results may vary, getting stable results is a process of trial and error (unless you use a proven industrial ink recipe).

where I live it's really hard to find some products (noodler's inks are my greatest passion). So the idea of ​​creating my own ink has crossed my mind more times than I can count. i've been searching to create my own recipies.

The only time I use food colouring with a pen is when I am decorating food. I use one of my glass dip pens and do calligraphy on fondant, cake icing, cookies or other foods. As for my writing pens - umm, use writing ink. 😉

I would like to ask if it is waterproof on paper when dried?

I left food coloring in a clear fountain pen for about 2 years it didn't even have a problem starting. (stored with nib up) It didn't even stain the pen. I had some cheap Chinese fountain pen ink destroy some cheap pens (I think it has alcohol in it). Go for the food coloring. The ink will not be waterproof though.

I used to make purple ink using Malabar spinach seeds.. it was fun lol.. the writings used to last for around a year or so.. not at all waterproof nor was any pleasant experience to write with.. but yeah