Homebrew PCBs

Having done PCBs down to 0.2" wide, I pass on what I do...

First, I use a scroll saw with a jeweler's blade (0/2) in it.  This is
only about 10 thou thick.  I cut a slot in a piece of 1/4" plywood and
tape the plywood down to the saw's table, this gives me a
zero-clearance place to work so that the board doesn't fall through
the hole, and is supported right up to the blade.

Second, I use metal shears (aka "tin snips") to just cut the pcbs up.
Works best with thinner pcb material.

Paper slicers only work on 0.31 or thinner board, and they don't work
that well with the 0.31 either.  It *can* be done, but it's not
pleasant.  Plus, PCBs are brittle - I would think that cutting
something that narrow, it would crack.

If it were me, I'd use the scroll saw.  If you don't have one, maybe a
small metal shear would be a good investment?