The Oilskin we use is a Traditional 120z Cotton Drill Fabric treated with an Antique Wet-Look wax waterproofing. The fabric is also used in the production of the Barbour clothing line and we use their "Barbour Thornproof Wax Dressing" supplied in a tin to re-pooof the fabrics.
The canvas we use throughout our store is both a 12oz and a slightly heavier 14oz Cotton Duck Canvas, popular with army tents etc., waterproofed using a dry wax method which would need to be reproofed using a Re-Proofing Bar. Canvas is stiffer than the oilskin and thus slightly more bulkier and heavier when rolled or folded up.
We use either a 55% Wool / 45% Blend on our Oilskin Ponchos & Bedrolls & a 75% / 25% Blend on our Hybrid All-Terrain Bedrolls. We find that the 55% wool one offers warmth, robustness, a nice solid weight and a stable sewing platform while the 75% woollen one offers you that little bit more luxury for the Hybrid Bedroll. We tend to steer clear of the 100% wool fabrics as one they tend to make you itch and second the fabric isn't as compact to sew to.