You will need a dipping can a few inches taller than the desired candle height and you will need enough wax to form the candles as well as to maintain the level of wax in the dipping can. Select a 1/0 square braid or a 30 -42 ply flat braid. You can use 100% beeswax, a blend of paraffin and beeswax, or a blend of paraffin, beeswax and stearic (see suggested blends). Also have ready a bucket of water to submerge the tapers in. Cut a length of wick 2 x the desired height of the tapers + 4 inches. Tie a metal washer or bolt to each end of the wick as weights. Cut a 2 inch piece of cardboard and make a 1/2 in cut on 2 opposite sides. Centering your wick, insert the wick into the niches so that the hanging lengths are equal. Heat the wax in a double boiler to 155F if you are using paraffin and stearic or 165F if you are using beeswax. Color and scent the wax. Pour the wax into the dipping can to about 1 inch from the top and maintain this level by refilling it with wax as necessary. Keep the dipping can in a hot water bath to keep it at the right temperature. Dip the wick ends into the wax to about 1 inch of the top and hold it there until you don't see any more bubbles escaping. Hang the cardboard on something so that the wicks can harden. You can also dip them in the bucket of cool water to speed up the hardening. When all the water has run off and the wax is cool, re-submerge quickly to the same level pulling it out slowly but steadily. Allow it to cool again. Re submerge as before and you should begin to see the wax building up. If it's not, then the dipping wax is too hot and is melting the wax each time you re-dip so let it cool down a few degrees before re-dipping. Keep dipping and cooling until the candles reach 1/4 inch in diameter at the thickest end. Then cut off the bottom of the candles evenly, taking off the weights. Keep dipping the candles until they reach about 7/8 inches (the standard) in diameter. Use a knife to shave off excess wax at the base of the candle before the last few dips. If you want, you can dip the last few dips in a high melting point wax to give the candle a hard outer shell. Immediately after the last dip, immerse your tapers in cool water to give them a shiny surface. Hang them up to harden completely.
A couple of notes about dipping - The candle will not grow if your wax is too hot and it will become lumpy if the wax is too cold so for each new wax blend that you use, you will need to find the perfect temperature for dipping. Don't let your candle get too cool between dips or the layers will not adhere to one another. Try to dip with a steady rhythm keeping the wax temperature nice and steady. It will be difficult to dip candles in a cold environment so try to work in a warm room.
Over dipping the tapers - over dipping simply means that your last dip is in a high melting point wax and therefore it creates a nice hard outer shell that eliminates dripping. The inner wax is contained by the hard outer shell until it is completely consumed. To over dip a candle, melt your high MP wax and add 10-30% stearic acid (unless you need the candle surface to be see through). Make sure the candle to be over dipped is not cold or the wax will not adhere well. Take your warm candle and dip it into the over dip wax and pull it out slowly but steadily. The candle will be soft from the high temperature. To get a nice glossy finish, immediately submerge the candle in cool water and then hang it carefully until it hardens. An over dip can be used to color a white candle too. Instead of using colored wax for the whole candle, you can use a regular white taper and just dip it into colored over dip wax.
Because tapers remain pretty pliable between dips, you can take advantage of this and create braided candles by braiding 3 skinny tapers together or twisting a pair of skinny tapers around each other. You can flatten your taper a little with a warm rolling pin (leave the base round so it will fit into a candle holder) and then twist the whole candle to create a twisted taper.
To seal in botanicals on the surface of a candle, 'glue' the botanicals onto the surface of the candle with some melted wax and then overdip in a high melt paraffin without stearic acid. You can add 5-10% microcrystalline (the type that hardens) to the paraffin for extra hardness.
*note*:not my articles,i get it from other website and I just want to share the articles, reproduced from: http://www.fromnaturewithlove.com/library/candledipped.asp