If you live in the U.S, Staples or Walmart has cardstock. I use mainly 67 lb. cardstock and 110 lb. cardstock. Some people use very thin stock for figurines, especially the hands. I also occasionally use very thick almost 1 mm cardboard for frames of ships. I get this from Michael's Craft stores. They aren't allowed to sell the left over paper from their picture framing service, but they hand it out freely, especially if you show them what you use it for. I have received many pounds of paper, picking up some UHU Brand glue. I showed them a ship, "Lilla Weneda" that I assembled, I doubled up the size, making it around 26 inches long. The manager was so impressed he gave me almost 5 lbs. of matte board of all kinds. Some pieces were rather large. Glad to see you back into the hobby. It is very satisfying to make something out of paper that rival or bests, in my opinion, many plastic models. Welcome to the forum, by the way!