I have found that if you line the belly of your stick bow with packing tape that has twine in it  the bow will become stronger and more resistant to breaking, poor man's sinew.  Also the twine used inside of farm combine belts does not stretch and is resistant to weather, perfect bow string!

Yeah, packing tape is great stuff, but I guess you mean the back also.  It would affect nothing on the belly - the only advantage would be that if the bow broke, it might not have the same force.