I was using 50cm paths in between 1.5m beds without boarding. I did need to put big pebbles on top to stop them blowing away, even after it had rained a few times, but after 6 months they are rotting down nicely and there are very few weeds. I wasn’t harvesting any winter crops, though, so the slipperiness didn’t matter last winter, although in future a better solution will be required for harvesting.
I think you can buy long rolls of cardboard of a defined width so you could use that and anchor it at regular intervals along your path.