Watercolor Paper in a Roll

I'm pretty excited!. Received the 51x10 roll of 156# Arches watercolor paper today. I cut off the size I need for the new Celadine Plumerias painting, and am trying to flatten it before I stretch it with water. Thought you might like to follow the process. I taped 6 small pieces of gatorboard together to have a lightweight board to attach the paper to. It will be light enough to turn (vs. plywood) as I paint. The outer edges of the paper are 36x46. The painting will be 30x42 The board is 46x48. I may have to trim the board to reach all sections of the painting.