The tar paper that looked so promising (shown below) and was the right thickness did not work out as well as I had hoped. I made a 5 layer test packet without veneers and found that it gooed up my blade, so onto plan B.
I finally was able to find and buy some poster paper that is thick enough at 0.68mm or approx. 0.27" which is very slightly thicker than the veneers I have. I found it at a Staples store not too far from where I live. It is as stiff as the veneers so I know for sure that it will be fine for making wasters and it is a whole lot cheaper than using veneer for the purpose. Now I just need to see if I have sufficient 1/8" ply for the top and bottom of the packet. If not then its off to buy a ply panel and THEN finally to make my first painting in wood patch packet! I hope I didn’t steer anyone wrong with my first post on this subject.