I agree with the things said above; slow growth induces bark faster, because growth overall is slower and the outer wood layer of the tree has time to oxidize and break down before it falls off. It's probably the illusion of actual bark. If a tree grows rapidly, this breakdown doesn't happen because the bark will be shed before it has time to build. In scots pines this is very visible from the coloration; dark plated bark on the bottom, orange flakes on top.
Actual quality bark that has deep fissures happens mostly in the ground. Because that's when there's energy to build wood mass. Bark so thick that it acts and breaks off like actual wood.
I have tried beating a tree with force, making slits and cuts. But it only grew thicker scars, not thicker bark.
I've been trying to dig into literature about bark formation, to see if there's a genetic trait related to cork bark for instance. But I haven't even found the scientific term for 'cork bark' to be honest. Bill Valavanis has introduced a cork maple(?) cultivar in the US that I stumbled upon during that research, but he wouldn't answer my message - understandable, he's a busy man.
I'm also willing to accept pollen from cork bark pine species, to see if I can use it to breed it into European pines. But that's going to take a couple decades at least, since I don't own any flowering pines at this time. I have that system laid out for.. other plants.. So I know how to handle, store (25 years max) and process pollen and how to do selective breeding by isolating and pollinating parents - it's not that hard actually and I can recommend everyone to try it for themselves if they have the chance. If you're interested, I'll write it down for you in exchange for some of the seeds you get from them.