Titanium is an alloy and it contains aluminum.
Call it what you will it does not matter at all but the more you dress up a pig underneath it is still a pig. Same holds true with precision. If you don't care about quality and only produce slop then precision bushings is not right for you. Precision bushings (or what ever our wish to call them ) greatly appeals to the makers who desires the highest quality, exact part matching and demands perfection.
Bushings is both an index point and a reference point. The material used can in some cases leave marks on blanks. The word 'stainless steel' is like me saying wood blank, there are quite a hefty number of different types out there and they behave differently. Some grades are more gummy than others. The L series that I have many sets of does not that. That being said .... If you sand the bushings and add ca with out cleaning the tube then yes you will have Grey spots streaks and lines all over the blank.
