Cleaning carbon paste off seatpost

maybe a fizik silicone seat post collar? they are about 1cm long so might cover some of it

the carbon paste i used does warn on the tube it will cosmetically damage the post

If you really want to know if it is pitted then look through a high power magniying glass. Alternatively take a photo of the seat post with you camera in macro mode; get as close as you can, with very good lighting (outside in daylight) and take a snap. Then zoom into the picture on your computer - you be amazed at the detail.

If the surface is very pitted then use T-Cut (for restoring paint on cars) to retore it. Be careful as this is a mild abrasive, so test on part of the post that is never going to show. You might want to try Duraglit wading (now called Brasso) as already suggested as this is a milder abrasive than T-Cut.

Good Luck

Try some degreaser, maybe?

Won't come off = permanent.

Dunno, doesn't seem to have affected mine but a few years ago trek published an advisory notice to the effect that people shoudln't use carbon assembly past on carbon fibre steerer tubes (for stems - who would do this?) because scoring around circumference of steerer tube would result in stress risers which might cause steerer to snap. Don't know that this ever happened in real life.

Dunno, I am out of useful knowledge now. Good luck. Although if it's that hard to get off, why not just treat it as permanent. Is it all that disfiguring?

May not be residue, may be permanent (physical) scoring. Carbon paste is typically a gel with granules of something suspended in it. The granules will eventually mark the surface of the seat post to the extent that it is below the seat collar. (So if you swap a seat post between frames with different bb-seat post clamp measurements and you end up with more seat post exposed you can see where post used to sit within frame.) If this is the case, nothing will remove what appears to be dried carbon paste.

brasso/duraglit wadding ....