See, that's what I meant EdT586
50 drops per ml / 5 drops per 10ml = 1%
I do know what you mean about tips.needles and how many variables there can be, but I was only referring to the original stock bottle tips. Long thin needle type, from Inawera as you mentioned. Other companies use these too and many DIY mixers know which they are and it's almost a known standard for those type of tips)
Thanks, corrected.
So now it should be pretty simple for using drops with the stock Inawera bottles ;P