Nice stuff, wood and size. I’m just bit surprised you vernish it before drawing the lines?
I tested a bit on scrap and if I don’t, the marker will probably bleed into the grain, making fuzzy lines.
Here’s the finished 13x13, with two more coats over the marker:
Not if you use the right markers. When (late 90s) I made a board, I foresaw this problem. I asked the people in the art shop what marker would not go fuzzy if I varnished the board. I think that I was advised a water-resistent marker. So if you explain what your plans are (varnish is not the only option; oiling, waxing are other options) an art shop can advise you on this.
I did 1 coat polyurethane, marker, then 2 more coats polyurethane, and the coatings did not make the marker lines go fuzzy. They get fuzzy if drawn onto raw uncoated wood, since the ink soaks into the grain.
Next time I get into some decent sized wood I’ll take some pictures and we can discuss.