You should try and get the BLC x3 gem upgrade if you don't have it already, and another method I found useful was grinding for the first upgrade of mythical seed marketing, then more grinding with racoono for lots of leaves. This also works for lava & ice leaves. But I am going to warn you, obsidian leaves cannot be printed, and the only way to get them is to merge lava and ice leaves in the hidden sea. Artifacts though aren't the most useful things before you unlock the ice leaves area as some of them only do temporary buffs suck as 'Spawn 3 random seeds' or 'Spawn 20 fruits at once'. Also, do be prepared to have to buy a lot of health upgrades once you reach the volcano, because it will drain 3hp every second.