Iv been examining and filing for an hour now, making sure each time that the mark is there and then gently taking each bit down.
problem is i now have something that resembles a bump key. Im concerned as to why i kept getting marks smack bang in the middle of each cut? its deffo gone wrong somewhere along the line but im really not sure where?
tried to take pics but hard to focus so close

any top tips as im sure this is more of an art than a skill