Linemaster

Great tool. Cannot suggest it enough. I have one of te soft spikes green spring loaded hairclip style ones. The tip broke so you need to hold the ends together to create a symmetrical line. This feels sturdier and even the ball friction fits into it so it wont move.

Too expensive, I don’t recommend it

Much more durabke than i had imagined. I thought they were an expensive gimmick, but actually they are far superior to notmal permanent markers…. I purchased the four pen bundle with red, green, blue and black.