After following this topic:
http://www.quiltingboard.com/t-56940-1.htm
I went out in search of paper on a roll to make piano keys. The office supply had a box of old fashioned fax paper for $38. (How on earth I can use the words "old fashioned" and "fax paper" together, I will never know!) But the young girl at the front counter did not even know what it was! She had to call a manager! That showed my age for sure! Anyway, same with adding machine paper. They had it, but I did not want to spend outrageous amounts on a dozen rolls.
I stopped at Lowes for something that was in the paint department and I inadvertently saw this. It is 6" wide x 180' long and costs $1.98 for the roll. They had it in several other widths, 8", 10", 12", and something narrower than the 6" wide that I bought, possibly 4". Don't quote me on the exact widths. I have not used it yet, but I think it might do the trick. If anyone has already used it, let me know.