the ink will travel up the tube for a couple reasons... 1 - capillary attraction in the space between needle bar and tube wall. 2 - the forward movement is a lot faster than the backward movement and you're using thick inks. using vaseline doesn't fix these problems but will keep the ink more or less where you need it to stay. bend your needle LESS, and relax all the rubber on the machine AS MUCH AS POSSIBLE ALWAYS. slow down the machine for thick inks, no matter what. i don't think the brand of needles matters, only that there is enough room between tube wall and needle to avoid capillary attraction.