They also come in different colors and patterns Cardboard Tubes. You may want to consider the object you are shipping and the reason before purchasing a cardboard brown color or for something exciting for a holiday or birthday. Mailing tubes also come in heavy duty forms which are designed to hold up to damage while being shipped. You might want to use the heavy duty cardboard shipping tube when shipping something internationally. You can purchase cardboard shipping tubes at the post office, office supply store, shipping stores, and can be ordered online.