What is the name/Where can I find long, thing, stiff wire/rods for LED Cube

I’m looking for a long thin stiff wire or rod that I can use as vertical supports for my LEDs.
If possible, it should be as close as possible as the leads of an LED. And I don’t know if they come in small pieces or one long piece that I can cut up.

Now I know I should’ve made my cube smaller/tighter and there are a few things I could’ve…would’ve done differently to make my life easier, but I already soldered the anodes horizontally and cut down the cathodes of my LEDs. And these were expensive RGB LEDs. Suffice to say there is no going back.

Which retailer would have what I am looking for? And is there a name for what I’m looking for?

Thank you very much!

In the US most decent hardware stores will stock "piano wire" with their other steel/aluminum/allthread/etc. products. Probably find it at a craft or hobby store as well.

This is used for making springs, so yes, it'll work.

Model engineering suppliers will have lots of options. Brass rod might be good as it is easy to solder.