Pillar candles are probably the best known type of candles and a real "classic".
They exist in an incredible variety of shapes, sizes and colors. Familiar shapes include cylinder and square, but you can also find more unusual shapes like star, pentagon, hexagon, whatever-gone, sphere, you name it!
But the common point of pillar candles is that they're poured into a mold and are, once they have solidified and have been unmolded, self-supporting, which means that, unlike container candles (wax poured into a container in which the candle will burn) and votive candles (placed and burned inside a fitting holder), pillar candles are burned as is, without the support of any container.
As I just mentioned, pillar candles come in an almost endless variety of shapes, sizes, aspects and colors! The only limit here is your imagination.
A pillar candle can be made of a single color or successive layers of different colors (these layers can be horizontal, oblique, alternated oblique, even vertical!)... it can also be made of little pieces of wax - same or multiple colors - covered with hot paraffin wax. These little squares of wax are called chunks and the resulting candle usually bares the name of chunk candles. Chunks are the ideal way to use the small amounts of wax left at the end of a project.
Another variation involves a mold filled with ice blocks over which hot paraffin wax is poured. The result is a candle full of holes, pretty much like a piece of cheese. You can use one of the many hundreds of metal, polycarbonate, rubber, ... molds available for purchase or use your imagination and search for everyday (or not) items that can be used as a candle mold or you can even create them yourself from scratch!
As you can see, no shortage of possibilities here and that's one of the great things about candlemaking: even after 20 years, it is possible not to make the same candle twice ;-)
All the techniques I've talked about (or will talk about) are explained in great detail in current and future projects.
The wax formulation used to make pillar candles in combination with the right wick choice - VERY important - allow the candle to burn by itself without the help of any container, unlike votive candles that need a fitting votive holder and container candles burned in the container they've been poured into.
To achieve this result, the wick size must be calculated to create a melt pool with a diameter almost identical to that of the candle itself. Moreover, the wick must burn hot enough to vaporize the paraffin contained in the melt pool quick enough to prevent the candle from "leaking" or the flame from drowning in liquid wax.
Too thin a wick will create too small a melt pool and drill a hole through the center of the candle (called a tunnel); too thick a wick and it will produce black smoke and/or leaks of wax down the candle sides.
The choice of the right wick is probably the most difficult aspect in candlemaking but it is also where 90% of a successful candle resides!