I traveled for work for years and always used the small toothpaste tubes for travel and filled them from the big tube when I was home. I have made and printed 3 different threaded tubes and every time I got a new tube of toothpaste one of the ends was the wrong size/thread. Rather than swapping out the different sized adapters, I just made a tube with different sized ends that taper inward. It works on everything so far and much easier that trying to keep the ends of the tubes meshed so you don't make a mess.