Best thing to use is hardboard pinned or stapled down (check the length will not go through the boards and into pipes wires etc) with the edges sealed to the skirting with flexible paintable mastic. Paintable is better than silicone in case you get any on the skirting above the carpet level.
Slightly warmer than just paper and a good seal to the edges where a lot of draughts arise. And can be reused if the carpet is changed.
I can see no problem however with using lining paper if you wish as it was common for old newspaper to be laid first, really interesting to read the old papers when the carpet was lifted years later
