Sharpies are alcohol-based… If you use them you can’t use any type of alchol-soluable paints over them. Ever… Those others he showed are types I’ve never used… But then, I don’t use automotive-grade primer either… Styrene doesn’t need priming, and I wish people would stop telling others to do it…
The grey primers from Wal-Mart or Krylon and the like are ok, but they work for me as finish-colors… The Wal-Mart brand, “Tru-Color” primer is a good substitue for USAAF Neutral Grey, IMHO… Overall though, priming is just adding another layer of paint, and in some cases, two layers, since the primers are relatively thick, especially if you use a primer-surfacer… Primer-surfacers work to not only act as a primer, but also to fill tiny sand-scratches and other imperfectections… It’s quite porous and needs more paint to be fully covered, as some of the color is absorbed into the primer…
I’ve never experienced the “transmigration” he spoke of, but I’ll bet a dollar to a dime the culprit was the primer… The only model I ever completely pre-shaded with a Sharpie was a Hawker Sea Fury, and I did the pre-shading on the inside of the fuselage and wings, where the paint never made contact with the ink anyway… The results where that I could barely see the shading, and I wanted it to be more pronounced, so I started post-shading all the little stuff and the panel lines… But it still showed… Just not like I wanted it to…
Also, that model depicted was covered with huge (for the scale) recessed lines… That type of detail calls for a post-painting wash during the weathering process… Especially in that scale, IMHO… I would have used either an oil-wash or a tempera-wash… And, it would have been only a few shades darker than the paint used for the finish… A dark pin-wash would have worked in the recesses of the flight-control surfaces…
Very few aircraft benefit from a pre-shade vs a post-shade, IMHO… It all depends on the color of the finish though… It’s one of those things that really looks good, but isn’t all that accurate up close… Scale distance is the factor there…
At any rate, I’ve been ok with using Sharpies, but I only use the “Ultra-fine” tip… And that’s only IF I opt to pre-shade, which doesn’t happen very much…