Model-makers' styrene sheet? Available in various thicknesses; BITD I remember it in thicknesses from 5 thou up to 60 thou (about 1.5mm). 5-thou is thin enough to bend almost like paper.
And you could build up a laminate from pieces of 5 thou, if you wanted a wedge; use liquid styrene cement (from a bottle not a tube - apply with a brush) to fix the shimming pieces together.
(I have NOT tried this! In particular, liquid styrene cement might damage body finishes, if spilt. So, YMMV.)
[quote name='Nostromo' post='976339' date='Oct 3 2010, 07:46 PM']OK . . . any thoughts much appreciated . . . . . . .
Just measured up my PBass up . . . . the neck pocket is approximately 95mm long . . . . and the scale length, nut to bridge saddles, is approx 865mm long.
So by calculation we can deduce the following:-
Assuming the shim is a wedge triangle tappered from 1mm to Zero within the neck pocket, then, (by the maths of similar triangles) assuming also that we maintain the relative action height of the strings relative to the fretboard, then, that wedge shim, of 1mm thickness, will raise (or lower - depending which way round you introduce it) the strings 9.1mm from the saddles at the bridge.
This means that for every 1mm increase/decrease of clearance over the saddles that you wish to achieve at the bridge by the introduction of a shim, then, your shim wedge triangle taper needs to be approx 0.11mm thick at its fat end - privded that your neck pocket is about 95mm long to achieve that relative string height change of 1mm.
If your neck pocket is different to my PBass then the ratios change obviosly.
Funny thing about all this is though . . . . I still dont really have a clue what type/thickness of card shim material would be 0.1 or 0.2 or 0.3mm thick.
For my project, I need to raise my strings about 2 to 3mm over the bridge . . which means I need a shim wedge somewhere between about 0.22 and 0.33mm thick ? . . .
I woudn't have the slightest idea how thick a business card is and I've got no way of measuring one ! . . so I still dont exactly know what to use for my shim ! . . . ha . .
All that work and not really much further forward ! ! ! . .
[/quote]