Negative action - https://www.dumonttweezers.com/Tweezer/TweezerStyleList/34
start looking under standard tips on the left see how many different Dumount tweezers there are.
The negative ones however are of little use for watch things imo, its hard to explain, but you are not clamping on to the screw, you're using the tweezers like finger tip extensions. You have to feel, and you vary pressure depending what you are clamping, weight size and geometry, (to much: ping! to little and the part slips out or out of position). You also have to often let up just a tad to push the part into something to position it, rotate it a bit, etc.
I don't mean to make it sound more than it is, but its deceptively difficult at first to pick up, position and place small parts. Things improve with practice, but you are scuppered without good tweezers. High quality screw drivers and tweezers are high on the list of first tools to buy, probably in the top five along with a loupe, case opener and hand removing levers....you need them before you service your first watch
Trev, I believe the biggest in Canada is Perrin. Even if not into horology, they have unique tools that would be hard to find elsewhere....where else are going go to pick up #6 Swiss cut file? (better take along a week's worth of lunch money though lol)