Star Wars special effects question.?

Question

Nowadays it's done by computer, but back in the original trilogy, to make the special effects for the lightsabres to glow the blade of the lightsabre was painted with a type of paint which does something like reflect light.
What type of paint was it?

Answer 1

Acutally, I think the original light saber fights were filmed against a blue screen & the saber blades were painted in at a later time.

Answer 2

Phospufluorescent paint.