Guild Wars 2

Let’s say that I have 4 rare runes that I want to throw in the mystic forge. For one of the runes, I actually have a quantity of 3. I don’t see a way to only throw in 1 of those 3. Is there some way to control the quantity of any item that you throw in the forge?

Use Alt-click → drag to split the stack in your bag.

I figured it had to be something like that, thanks.