One of my most consistently popular posts on this blog is the Candle Omens post, indicating many many people want to know about how to read omens for their spells through the augeries of wax or flames. When I perform spellcasts for clients, if the work I have done involved a candle spell, I will usually report on the condition of the flames, smoke or interesting activity with the wax.
And yet, how valid is this for determining spell outcome? In my own experience, I have had candles that burned badly result in brilliant successes, and candles that burned well lead to dud results.
The first thing to keep in mind about reading omens in candles it that it really shouldn't be done if you are inexperienced in candle burning, OR if you are using an unfamiliar brand of candles. In both cases, it can lead to falsely assuming a normal event is something abnormal or significant. For example, there is a particular type of pullout candle which I have to go out of my way to avoid buying, because it invariably puts itself out while burning. This has no actual effect on the spell: it's merely a badly made candle. (All the same, I don't want to buy it because I want my candles to burn all the way instead of needing to be relighted every 20 minutes.) A candle going out by itself is generally a very bad omen for a spell -- just about the worst you can get -- and if I were unfamiliar with the brand, I'd assume I'd received bad news. (And did assume it, the first couple times I used that brand.) Similarly, there are candles that always smoke or always drip a lot of wax or always burn with a low, dim flame. If the candles ALWAYS burn that way, then it means nothing.
Secondly, while everyone is anxious to see predictions for how well the spellcast will or won't succeed, my experience is that one should not take the candle omens as an absolute. The candle burning omens only depict how difficult or easy a time the spirits have been having during the spellcast: what happens afterward is still up in the air and in no way fixed. Naturally, if the spirits have been having an easy time, it's more likely that you'll get your wish; but it's not out of the question for things to go pear-shaped after the fact. Similarly, even if the spirits have been finding difficulty in bringing what you wished for, they can still come through to produce perfect results. Candle omens are merely progress reports, not the final judgment.
Candle magic seems to be another of the European additions to hoodoo -- it is virtually unknown in both African and Native American magic, and perhaps for the good reason that candles themselves were not often used by these peoples, with fires or oil lamps being much more typical sources of light to them. The use of candles in hoodoo appears to have started in areas of the United States with a more heavy Catholic population, and it may be that they are derived from the Catholic practice of altar lights, novena lights and votive candles. (Interestingly, a 1919 book about Catholic practices indicates that the votive light had only become popular "during the last few years.") In the early 20th century there was still not a lot of designation between hoodoo folk practices, and voodoo or other spiritualist church practices. It is possible that candles were originally being used in the formal religious-style services of the spiritual churches and voodoo ceremonies, and from there grew and spread into the folk magic practices.
Candles made from paraffin wax or beeswax -- sometimes adulterated with other waxes for one reason or another -- have been most typical in hoodoo practice through its candle-burning era (for, candle spells were uncommon in hoodoo before the 1910s.) Church candles traditionally needed to be made, at least in part, from beeswax; and also the numerous European grimoires and occult texts which became popular amongst the hoodoo crowd circa 1915 promoted the use of beeswax candles further. The paraffin candle was invented in the mid-19th century and took some time to perfect (early versions had some issues with too-soft wax that melted or bent in hot rooms) but finally became the norm around 1910, and when aniline dyes became popular around the 1870s, it gave the ability to easily tint the candles into bright colors. Colored candles seem to have initially been used for the sake of decoration, but in time hoodoo practitioners began assigning significance to the colors. One of my sources for the book Conjurin' Ole Time (now reprinted as Conjuration) disclosed that in the 1910s, blue candles were most often used for love, and so were pink sometimes used. White candles were used to bring marriages. Black, of course, was used to produce harmful effects.
Early hoodoo candle spells (before 1940) seem to have been simple affairs where an appropriately colored candle was burned, often alongside or on top of some kind of spiritual ingredients for working a spell, e.g. on a jar of honey for a sweetening spell, over a name paper to influence someone, or simply burned in the house to attract certain influences. Things started changing around 1940, however. In that year, Henri Gamache's Master Book of Candle Burning appeared; it is unclear whether he was promoting already-popular candle magic practices or whether he had invented a new system himself; but from that time it became common to dress candles with anointing oils and form them into significant arrangements where individual candles represented something or other, and would be made to move around the altar during burning in order to represent the transformations desired, in a mode similar to treatment of "voodoo dolls" and other like objects.
In a move attributed to an influx of Latin-American immigrants in the 1970s, glass-encased candles started growing in popularity among hoodoo practitioners -- to the point where nowadays, some people don't even realize that other kinds of candles can be used in spellwork. Glass encased hoodoo candles are usually just colored candles with a label stuck or on printed, which marks the candle as intended for some particular purpose ("Crown of Success" or "Bring Back Lover" or what have you.) Most brands come without any special dressing and either the user arranges for the candle to be dressed at the shop where it's purchased, or else dresses it himself at home. Most often, hoodoo practitioners burn these candles by themselves or on top of petition papers and photos; but sometimes they ca be used to replace the standalone candles in Gamache-style workings.