Ah, I love this stuff. Don't use it much for routing to be honest, have used it for sanding though. Mainly it goes to line drawers, shelves, boxes etc to protect tool edges in storage. My best buy was 6 x 2 feet for £4 IIRC, at the local discount store. Quality all appears to be much of a muchness, the price difference is usually down to size. I think the stuff they sell for stopping stuff slipping on trays and so forth in kitchen places is pretty much the same too, if you favour pastel shades... :lol:
The sacrificial cutting table for the router is an idea as old as the hills; I hope that wiley Fox didn't get paid too much for rehashing that one. Chipboard is indeed the stuff to use; less dust than the dreaded MDF and a cleaner backing to the cut than ply. Pretty nearly the first bench appliance I ever made, back in the days when I believed the router was the only tool I'd ever need. :roll:
Cheers, Alf