Stiff zip - help please

[LIZS]

Planning to wear a favourite dress at the weekend and zip keeps catching. It is a bit tighter than on previous occasions but there still seems to be room to do it up. Do I recall soap helps ?

vaseline along the zip usually works for me

I find spraying furniture polish on curtain rails helps when they're sticky so might work with zips too. May be difficult to avoid getting it on the dress though.

Run a plain "lead"pencil along it. The graphite in the pencil will make it run smooth.

Bees wax is what DD uses on wetsuit zips

I was going to suggest a pencil too

Another 'pencil' suggestion.