Broadsheets are easiest....one Glasgow Herald = one 20cm wide basket
They're surprisingly robust too, and a good way to practice without having to keep willows damp while you work
Not waterproof though, even when varnished, since you can never get into all the nooks and crannies when the weave is tight.
Hard work for kids to manipulate the tight rolls. If you start off with the base crossed over, I found that climbers accessory cord (thin paracord type stuff) was the beesknees for doing a quick weave round to hold it all in place before I started twinning. It pulled free neatly afterwards and the paper beat down into the weave ver tidily.
If you fold the newspaper into strips about 5cms wide though, they weave very well and do checkwork (look at the woven birchbark for examples) baskets and matts. Children manage those very well indeed.
I did try loose rolled strips but they tore when any effort was used to keep the basketry taut.
What does work is halved long sheets twisted and plyed together just as we make cordage. It makes a paper rope that weaves very well indeed
atb,
Mary