YouTuber 'Custom Trackmaster' Has a video or 2 on how he relines. I believe he uses a Oil Based Paint Pen (don't know the brand) but he actually slices the felt tip in a flat wedge.
Here is one video showing his pens and one showing his chisel point
Here is one video showing his pens and one showing his chisel point
![[-]](https://www.blueplastictracks.org/images/collapse.png)