Home made, cut from a black adhesive sheet/tape. Now replaced with black markings (BIC Onyx permanent marker 1481, that can be removed with ethyl alcohol).
IMHO - The issue with Sire fretless basses is that side dots are placed between the frets, like on a fretted bass, and not aligned with the ghost frets (which is what I prefer).
That is a deal-killer for sure. I can't believe Sire is dumb enough to do that! I have an old fretless Carvin with dots between "frets" as is sometimes the case with lined fretless (they use fretted necks with stripes instead of frets) but on my Carvin, lines are white and clearly visible from the edge of the neck so the fretted dot positions are not a problem. But for a non-lined bass to have dots on fretted positions would drive me insane in no time. That bass would immediately have to go back!
(I noticed on yours the lines are white but not visible from the edge of the neck because it's bound and white too. I could not live with that in a new bass. For a used bass I might get a black marker out like you did, but for a new bass I expect it done right)