Ahhh... I see !!...you use attys for testing new flavors .....it's all starting to make sense to me now.I never used cartridges so I am no help at all with that. Hopefully someone that is familiar with them will chime in. I do use attys for testing new flavors but I drip 3 drops directly onto the bridge.
The cartridges don't seem to be as good as cartomizers.
Cartomizers seem like a better way to go!
anyhow....it's still all experimentation at this stage.
I may try and drip a few drops onto the atty's bridge and see what happens.