Bonus Potential.

What items can I use to add bonus potential to an item with no bonus potentials?

Special Bonus Potential Scroll, Bonus Potential Scroll... You can gain hidden bonus potential from crafting (fusing).

(Special) Bonus Potential Scrolls are currently broken though, you can only use them if you're trying to put potential on an item that is already equipped. The scrolling UI doesn't work with them for some reason.

I know special bonus potential scrolls are sold in the CS and you can get them from black cube frags, but what about bonus potential scrolls?

From one of the exchange quests in Masteria:

(20) Each - Windraider Badge, Stormbreaker Badge, Nightshadow Badge, Firebrand Badge, Crimson Heart

Tablet for One-Handed Weapon for ATT
Tablet for One-Handed Weapon for Magic Attack
Tablet for Two-Handed Weapon for ATT
Tablet for Two-Handed Weapon for Magic Attack
Tablet for Armor for STR
Tablet for Armor for INT
Tablet for Armor for DEX
Tablet for Armor for LUK
Tablet for Armor for HP
Gallant Scroll for One-Handed Weapon ATT 65%
Gallant Scroll for One-Handed Weapon Magic ATT 65%
Gallant Scroll for Two-Handed Weapon ATT 65%
Gallant Scroll for Two-Handed Weapon Magic ATT 65%
Potential Scroll
Bonus Potential Scroll 70%

Dunno if there are any other ways of getting them than that.

The Ninja Castle questline gives out a Bonus Potential Scroll near the end. I forget the percentage on it though.

(Special) Bonus Potential Scrolls are currently broken though, you can only use them if you're trying to put potential on an item that is already equipped. The scrolling UI doesn't work with them for some reason.

I can confirm Special Bonus Potential scrolls work with the new UI, even if the equip is not equipped. I've used one, after trading some black cubes fragments, on my unequipped Gollux Pendant.

I can confirm Special Bonus Potential scrolls work with the new UI, even if the equip is not equipped. I've used one, after trading some black cubes fragments, on my unequipped Gollux Pendant.

Oh I haven't tried the ones you get from cube fragments, the ones sold in the Cash Shop/bundled with Carved Slot cubes don't work though. Or didn't when I checked a week or two ago.