Machine needles for blackout fabric?

[Highlove]

I'm about to do some curtains using blackout fabric for the first time. I read that I'm supposed to use leather needles. That right? What size? I've got a mixed pack of 90 and 100. Does it matter which?

Any other tips much appreciated - anything I need to know?

Oh - also can you iron it? Which side?

I've used regular sharp needles number 12 or 14, denim needles would work as well. Use a cotton cloth when pressing and a medium heat, just in case.

Blackout fabric has got a lot thinner over the years, when I first made blackout curtains it was often really thick. Now I just treat it like normal lining fabric. Are you hand or machine sewing?