Starting yesterday, I have been making tubes. I use two sizes of dowels, quarter inch and 5/16 inch. I use good ole'fashion computer paper. I have made about 80 tubes, so far. I don't worry about the exact number of tubes of each size. It is about half of each size.
After rolling a tube using elmer's glue I finish with two or three pieces of masking tape to secure the flap.
I bought a 2.5 lb tub of white modeling clay at Walmart. It cost a few cents over 5 dollars. It is essential to seal one end of each tube. According to the label, the clay drys slowly. So after three months the tubes will be ready. If I have completed all tubes by first of January, the clay will have plenty of drying time prior to March 15 (Pi day). Pi day is the day most mason bees recognize as the beginning of the mason bees life cycle.
Soon I will begin cutting and shaving the bamboo tubes.
It is essential to have a good supply of black bamboo tubes because mason bees prefer black bamboo tubes to all other types of tubes.