tips for a really staiff zipper please?

[happyjack12]

got a lovely jumpsuit to wear at weekend, but the zipper is so stiff, any tips please?

Pencil "lead". It's graphite and make a good dry lubricant. Just draw up and down on the zip with a pencil. be careful of excess.

I was going to say pencil but Goldenbug beat me to it. It really works.