Can people just stop writing about honey being used in ink like it's a binding agent alongside the gum... Just try it and you can enjoy Ink That Will Never Dry.

Here's a recipe attributed to Ibn Muqla that I found in more than one serious publication. You combine the following and cook them slowly until smooth:
3 ratl lamp black
9 ratl water
1 ratl honey
15 dirham salt
15 dirham ground gum
10 dirham ground gallnut

These units of measure vary too much to translate accurately, but roughly speaking this means:
1200g lamp black
3600g water
400g honey
45g salt
45g ground gum
30g ground gallnut

Notice anything strange?

There's about 10 times more honey than there is gum. And this alone tells you there something not right here. This "ink" is going to be a velvety black syrup. I can vouch for that because I tried it. It looks dry—until you touch it and it smudges like shoe polish.

The amounts of gum and honey must be swapped for this to make sense (but I haven't tried it and can't guarantee the result). Another thing: 30g ground gallnut? For 1200g soot? That's a homeopathic amount. It's at most a placebo, completely pointless.

So what's going on here? One possibility is the conversion is way off. The value of the ratl varies to a ludicrous degree depending on time and place, from 84g to 1,500g and more. If the former was meant, it might just work. Without reliable dating and place of origin, we can't

tell what the measurements mean in absolute terms. Another possibility is that errors slipped in as it was copied and re-copied down the centuries. In any case, you would never have more honey than gum in a recipe. And I take the Ibn Muqla attribution with a whole lot of salt.

Here's another thing about honey: it's also sometimes touted as being a preservative in ink preparations. Don't dream of it. Nothing encourages mould as much as honey in your ink. You only need to activate yeast once to know how much micro-organisms LOVE the stuff.

Liquid inks in that period were never meant to keep long. They were expected to spoil quickly, as we know from the frequent injunctions to stir the inkwell daily and clean it frequently so it doesn't smell. Some antibacterial additives were used for black inks (hibr), which

wouldn't be altered by them, but the single best preservative was to dry any colourant that allowed it and store it in a dry state. No moisture, no problem.

The misunderstanding about honey seems based on statements like this (I don't have the source at hand):
اما العسل فايحفظه على مرور الايام ولا يكاد يتغير عن حالته
"As for honey, it preserves [the ink] from the passage of days so that it doesn't change." What does it really mean?

There's one property of honey (and sugar) we know of for sure: it's a humectant. It captures humidity and stores it. This is why honey or syrup never dry. 5% honey in an ink preparation (the maximum amount advisable) will still hold humidity, and this is the key: the ink

WILL dry—but it won't get bone-dry and brittle. It'll keep enough moisture to be supple and continue adhering to the support, instead of cracking and flaking away (as midad is esp. prone to do, since it rests on the surface without chemical binding). That's honey's contribution.