I've been taking sugar cubes for the whole summer and I think its completely efficient. I can usually see one side of the cube covered in light brown. I guess the liquid is suppose to be that color. it seems like at least one drop but it has worked everytime.
dropping it on cubes is the cheapest way to go, and most efficient. the whole deal with blotter is that what you put on that is lucy in a little different state than how she's chillin in your vial. so if you tried to drop from the vial to some paper, you'd be losing the usefullness of lucy. i'd go with the sugar cubes, but try something fun if you've got the opportunity, man. i've had gummies, sweet tarts or smarties, pez, etc etc. just go for anything edible and absorbent, that won't break down too much from a drop or two of liquid. usually something with a little dip in it helps. let it dry for a good while, and enjoy.