Regarding dosage of this amazing material...
It underscores the differences between individuals that i get a very nice, albeit somewhat light, trip off of 8mg. Though, i'm small - ~130lb (60kg, so 0.13mg/kg - i'd love to see some others' doses in mg/kg). Also, i can't understand how someone wouldn't enjoy a threshold dose with some good weed, but to each his own.
Okay this is getting really annoying. How is anybody supposed to make an educated decision on dosage when there are so many variables?
So you don't have a good scale.
Go down to your local sketchy convenience store, and buy a scale accurate to 0.01g. Weigh your supposed 100mg of 2C-I, and observe to what degree you were ripped off or got a bonus. You now know the weight to within 5-10%.
Then dissolve it in a known quantity of liquid, and measure that*.
How to measure the liquid? From the kitchen section of your local supermarket, you can get a turkey-injector** syringe that measures ml's with a level of accuracy acceptable for this purpose.
I'd make up a mixture of like, 2mg per ml or something (i do 4mg per ml, but i'm not measuring doses with a turkey injector), and store in away from heat and light. For solvent, use distilled water, or preferably, vodka (or 50:50 vodka:water - the alcohol is just there to keep crap from growing in it).
Do not store it in a nip bottle unless you label it. You wouldnt want someone stealing your booze (bad enough) and wind up tripping (you'd probably get in hot water over that)
*Tip: put the 2C-I along with like, half of the water, into the container. Then, with the rest of the water, rinse the bag out, and any tools you used, so as not to waste any precious magic.
**Do you think i'm joking? ~30 ml plastic syringe, lovely standard fitting on the end, and a 2 inch long needle on the end. You're supposed to fill it with seasoning and shoot up your turkey with it. Google it if you don't belive me. Be sure to get one with ml measurement.