Ok. what is the diameter of those candles? You say taper, but they are a poured taper? How long are they?
All waxes shrink when cooling. Some just more than others. Paraffin will pull in at the sides a lot more if there are other objects too close (uneven cooling).
Make sure your mold is warm when pouring. Even if it is plastic or silicone put it on low in the oven or try to heat with a heat gun. You don't want to shock the wax. Then after pouring, pound the molds to release as much air as possible. Then as the candles are setting up you will "poke and repour". Use a metal or wood skewer to poke relief holes along the wick and pour hot wax in the holes. You will see a lot of air bubbles come out. You may need to do this a couple of times.
Hope this helps some.
Lyschel
