Right. Now, after doing a good amount of projects involving it, its time to write in depth about micromaille.
Supplies for micromaille can be bought at a jeweller's supply store - a real one or online. Usually you will find copper with some plating - in my case gold-plated, rhodium plated, bronze plated copper rings, but if you have the money - you can even do real silver for example. I don't think anyone has the money to do real gold...
The links will be moderately expensive too - for the amount of money needed for a chainmail shirt, you will barely get enough to fill in your hand.
If you need something specific, because the stores will only have preset sizes, you can buy wire and make your own links. The wire is sold per meter usually(at least where I buy) and could be well under 1mm thick.
As an example - here are microscopic links I made by myself - so tiny I could fit them under my fingernail.
2 TOOLS
First of all you will need the smallest pliers you can find and then some! Those are pretty small but they are still not very comfortable for the job - I'm thinking about customizing them a bit. The nail clipper? Well...Its what I used to cut the home made microlinks above.
TIPS
VERY IMPORTANT!
And related to the above mentioned thing about the magnifying glass. ONLY WORK AT GOOD DAYLIGHT! Don't try to work on a lamp light or if its dark! Just don't! You will be looking at an optometry cabinet in no time. Its just not worth putting on glasses for this, believe me.
Forget about speedweaving. The rings are so small the only way to actually work is 1 by 1. Its impossible to grasp them by hand properly and they tend to slip a lot, so just do it 1 by 1.
Get something with a lot of tiny boxes. Like a fisherman's case or a tool box or something. You will need somewhere to keep those links sorted out and safe from getting spilled all over the floor. Good luck gathering them if you do!
That's all I can think of for now but I will add more later probably. Might split this into several posts too.
