I have a Jackson Dinky and while changing the strings a few weeks ago the low E string apparently put too much pressure on the side of the stock nut and snapped a small chunk off leaving me to replace it. So I ordered a new pre cut nut from Graph Tech. I removed the old nut from the neck and using my digital calipers measured both of them and finding that the stock nut (with the factory glue removed from the bottom) was 0.28mm taller than the new pre cut nut. The new nut also isn't as deep in the slot as the old one was, however, that is the nut that was said to be a stock replacement for this guitar.

Now I know for a fact that the old nut was just a hair on the low side and I was thinking about shimming it previous to it breaking, but now I am left having to shim the new one to get the height even in the ball park. I have been doing some research and found that some like to use sticky labels as shims, but I am thinking of using something more along the lines of a thin (.25mm) piece of styrene plastic that I have from modeling and just super gluing that to the bottom of the new nut. If this is "OK" then I can add a few layers and sand it down to a perfect thickness for an optimal shim.

Will this introduce any unwanted effects or possibly degrading the tonal quality of the instrument? Is there a real reason why I should use paper as a shim over a more solid piece of plastic? I would use a brass shim but I am having a rather difficult time finding one with the thickness that I need.

THX for any and all help.
dude i had the exact same problem with mine.
the reason the chunk snapped upp is probably the string gauges, it'll happen if you slapp some thick ones on and then go back down.
so make sure you dont do that
but anyway, there's absolutely no way you can just put it on like that?
I am a little confused, I don't fully understand what you mean by "put it on like that?" The new replacement nut is too low to start off with and I HAVE to shim to get it close to where the stock nut was, even though that was a hair too low also. I like a low action, but not where my strings are coming in contact with the frets lol. Also the strings that I am replacing are the same that were on there previously, just not rusted and worn out.
I don't really need a lot of height compared to where the stock nut was, IDK maybe .2mm would have been plenty to get it in the zone. Would the styrene plastic be acceptable for shims, glued to the bottom of the nut?