by Dormammu
In season 1 and 2, card quality is good. I have played sixty games, mostly unsleeved, with no signs of early wear.If you want to partially sleeve, it would be the mythos cards, as the Elder One mythos cards are used more often than anything else. Discovery cards really don’t need sleeves at all.
I haven’t seen the season 3/4 cards to speak to their quality and whether it’s any different.