Ok, I have to shim the Neck of my Bass. I need to raise the neck at 16 fret up to 1.5 - 2 mm. I found there are two ways for shimming the neck. 1- Full pocket flat shim 2- Angled shim (I found it should be full pocket too and partial shim at the end of the pocket is a no no and it might lead to ski jump. How to Shim a Bolt-On Neck — Haze Guitars). I want to try flat shim because it makes more sense to me. It is easy, no need for calculation and at the first try you are done, Natural(there should be a flat surface of wood in the first place but it machined too much deep in factory so I undo it with a flat shim) but the angled shim is more complicated in calculating and crafting also you may have to do it multiple times( I mean making a shim, put it in the pocket, tighten the neck screws, tune the instrument and nope you should sand it more...) Also tilting the neck by an angled shim changes the geometry of the instrument and probably increases the final scale length. I see the angled shim has more fans here but no body says what is wrong with a flat shim. Everybody only says you need a much more thinner shim that way(Angled). That's all. I can't consider it as an answer because it's not. So what do you think? What's wrong with a Flat shim!!?