I keep seeing that people use this for metals. What's a good place to buy it when you need it reasonably quickly, like within 7-10 days? Also, it looks like it needs to be mixed with something to work - would Matte Medium work okay? Thanks!

Welcome to PF Beatha.
You'll probably get more local sources soon.
In the meantime, have a look at El Greco's products:-
https://www.elgrecominiatures.co.uk/collections/printers-inks
There may only be three in the range, but they are excellent quality.
I find they mix well with oil paints.
Terre Verte with the gold gives a passable brass.
Black and blue with the silver gives a good steel.

Cheers,
Andrew

I use ordinary thinner to thin them with. Some say the carrier in Humbrol paints is good too.

Gary D

They need a dryer to dry them other wise they never dry. Humbrol carrier is a clear varnish and works well as a dryer. I use a very little amount of W/N Liquin and then Rectified Turpentine to thin the mix.
Cheers
John

Thank you, that's super helpful, especially the part about the dryer, which I did not know.

I don't use a drier, and I've never had a problem with the El Greco ones.
I leave them for two or three days and then use a dark pin wash for shadows. Next day a touch of the metal on the highlights.
However, be very light-handed when applying the wash. Heavy brushing will cut into the metal finish; so John's point is applicable if you want a rock-hard finish quickly.
As an aside, I've recently started using the acrylic Molten Metals by Darkstar Miniatures, and have found them very effective:-
http://www.darkstarmini.co.uk/darkstar-molten-metals.html

Cheers,
Andrew

Me too, and I find them to be excellent.

Chris

The printers ink seem rather expensive when so many other alternatives are available, I still have several bottles of "Rose Gold/silver" powders from way-back-when which are still as good as when they were purchased, I also quite like the Valejo "air" metal metallic's for swords and such like.

Steve

Hi Beatha,
You could try Liquitex Inks. wwwliquitex.com
cheers
Richie

I would suggest you try the dark star range beatha,they are very good and excellent value for money,alot of modelers use this range and they also do washes as well.