On Mar 21, 12:15*pm, dog-man wrote:

I tried using a fine jigsaw blade but it still chips the plinth
somewhat.

Blades help a lot. Not just small teeth, but anti-chip shaped teeth
(Bosch 101B) and a new, sharp blade. Even better is a "reverse" tooth
blade (Bosch 101BR) that cuts on the downstroke. Make sure any
pendulum action is switched off. If your jigsaw has an anti-plinter
plate (tiny gap round the blade), then use that, although they're not
a great help on chipboard.

Scoring doesn't work too well on chipboard, because it's too hard on
the surface to score easily, and the chips are so fragile they''re
especially prone to chipping. Scoring might help if you can score to
the depth of at least half a chip thickness.

Another trick is to trim with a router, not a jigsaw.