Where do I find one in Velan? So far I've found two mentions - "In a chest near a Nekker nest southeast of Hindhold" and "The old tower... Lornruk..." and there's noting there. I have the enhanced version, but can't use it.

It's weird, it's like recipes are randomly distributed between loot, herbalists and alchemists... -shrug-

Just checked - found enhanced black blood ans some enhanced bomb. No oils. :(

How are you sad, you just got some enhanced stuff!? Well, I guess, black blood is almost useless... Anyway, try looking near Hinhold (the fortress near Novigrad's border post, where you get the enhanced griffin gear, there is a harpy's nest there) move east from the fortress towards a broken bridge and I think that is the nekker's nest you mentioned--there should be a chest with the oil. If it's not at that exact spot try looking at some question marks south from that area, they should be nekker nests, check for chests. It's the only other spot that I can think of where I found reflect oil..I did the Griffin gear treasure hunt quest and Keria's quest around the same time, so I guess I got the location of the oil mixed up... :|

I'm pretty sure they're often random loot... but there's a herbalist just northeast of oxenfurt that sells all the basic oils.

at level 33 I still don't have some of the superior recipes for some of the oils.

It seems like certain vendors have updated inventories when you hit a specific level in the game. That isn't just for oils though, its the same for glyph crafting as well as armor/sword repair kit recipes.

Kind of annoying having to sift through all the merchants in the game to find something specific when you hit a certain level. Don't agree with this design decision.

It's definitely not random though with this stuff, certain things only become available at very specific levels.

Well, after looking yesterday and a few hours this morning I threw in the towel and resorted to cheating. CE + Ignore Crafting Material Requirements = enhanced relict oil.

I've got relict oil ages ago (no idea where), but can't for the life of me find hybrid oil although I have the enhanced hybrid oil recipe, but it's of course useless without having hybrid oil. I'm suspicious that it might be in White Orchard perhaps and I just never ran into it.