Dropper paint bottle totally acurate model for reference.

This ibncludes the 123D original file to use as you need ;)

Step 1: Buy / have a dropper bottle of paint

Step 2: Buy / own a meter.

Step 3: adopt / have a cat.

Step 4: Measure the paint dropper bottle with the meter.

Step 5: Record those measurements in a document.

Step 6: Lose the paper and measure the dropper again.

Step 6.1: In the middle of step 5 find the first measurement note which is your cat's new toy.

Step 6.2: Run all over your house trying to catch your cat, but realizing that it is a lost cause.

Step 7: Finish measuring and jotting down the new list.

Step 8: Go to your PC and use the new measurement list to model the dropper.

Step 9: Enjoy :)