Apart from the last Vanguard paint ALL my paints were done with a simple programme called ARC Photostudio which does not have multiply
Paint Shop Pro however does have multiply and it's a aprogramme a lot more sophisticated than the one I used.
On the layer palette where it says "normal" scroll down it's one of the options

Fading or lighhtening is best done with transparent whites over the top of the paint layer.
In over 600 paints I never found I needed to run a semi transparent paint layer over the details. In Photostudio I had to redraw the detail on a new layer

Garry