[jaclaz]

There are two aspects of the "difference":

1) The timber that was once a locally (or nearby) grown tree might nowadays be - while the same or very similar species - originating from some other country (with different climate/humidity/etc.) and thus be different at a structural level.

2) The timber was once seasoned over several months or even years time (again locally), while most nowadays is artificially seasoned very quickly (usually in a kiln or autoclave for a few days)

While you cannot do much for #1, except of course choosing the best batch you can find, the #2 (which is actually what makes the larger differences in stability and also strength over time) can sometimes be avoided by buying the wood before it is seasoned and season it yourself naturally (of course you need the space and time needed, for furniture or making of windows/doors seasoning for a couple of years is not uncommon).

The difference between artificially seasoned wood and naturally seasoned is essentially that the latter is more "stable", i.e. it will tend to crack and/or bend/deform much less.

[atty]

Awesome, thank you for the info!

Edit: not awesome that wood is lower quality of course, the awesome was for the explanation.