[anj026]

I've been looking back over what I have and it seems that the bigger the tube diameter in relation to the objective then the less the number of baffles required in theory. As the tube diameter decreases with respect to the objective diameter then the more baffles will be required to prevent off axis rays reflecting off the tube wall and onto the focal plane.
On the other hand you can do what Televue do with their refractors and not have baffles at all. They use high quality flocking material to line the inside of the tube. This effectively becomes continuous baffles and allows the telescope to be as compact as possible for it's aperture.
One method of doing this is to glue ground up walnut shell or similar coarse material to some card sheet and then paint it matt black. Roll the card sheet into a tube and push it into the telescope tube, gluing it at each end to hold it in place. Or you could just buy self adhesive flocking paper from Protostar on the internet.