I used a card former clad with kitchen roll which i "delaminated" to "1 ply". The trick I found was to hold the kitchen roll against the apex of the tent and drop on very watered down PVA from the apex to the base. Seemed to work okay.
If I was doing it again I'd mix in a little khaki paint into the PVA to give a better base colour to work from.
Hope that helps
vT