The definitive dictionary of Candle Wax terminology

CLP, MSDS, HT vs CT, COA… are the candle making terms bringing you close to your Flash Point?

Fear no more! All the terminology used in the candle making industry is now explained below here!

Alternatively, check our candle making FAQ or give us a shout.

AdditiveThe raw materials blended with wax according to a formulation, with the aim of modifying the wax behavior. Some examples of candle wax additives include Stearic Acid, for hardening; UV stabiliser/inhibitor, for preventing colour fading; Hard waxes (e.g. beeswax) and soft waxes (e.g. coconut wax); etc. Importantly, waxes that are classified as additives are often not intended to be used as a stand alone candle wax.
AfterglowWhen a wick keeps emitting an embers-like light after the flame is put out.
Bain MarieA method for safely melting components and ingredients, e.g., chocolate and butter in cooking, and wax in candle making. The method consists in placing a smaller container into a larger one, with minimal contact between the two. The space between the containers is filled with water, which is then brought to the boiling. As boiling water cannot physically reach more than 100°C at 1ATM of pressure, this method helps maintaining the second smaller pot at an event temperature and prevents over heating. Also known as Double Boiler.
BCFThe British Candlemakers Federation. BCF represents UK candle manufacturers and their suppliers.
Burn CycleA dimension of the Burn Tests, the Burn Cycle describes the behavior and performance of a candle repeatedly lit and extinguished over a set time. It might be a fixed amount of time, e.g., 4 hours, or until the melt pool (see definition) is full.
Burn RateA dimension of candle or wax performance, the Burn Rate indicates the amount of wax consumed an unit of time. Typically this is measured in grams/h.
Burn Test A fundamental step of the product development process where candles performance is evaluated at defined environmental conditions. See our article here.
Burn Time A dimension of candle or wax performance, it indicates the total amount of time a candle can burn for.
Chatter MarksMore frequently used in American English, this terms indicates horizontal marks, lines or rings that appear on the side of a pillar candle or container candle. These marks tend to happen when the wax is poured in a cold container or mould, or when the wax itself is cold at pouring.
CLP LabelsCLP stands for Classification, Labelling and Packaging of substances. This EU regulation requires that you create labels for your candles describing the risks related to them. Free CLP label generators are available online, like here:
COAShort for Certificate Of Analysis, this document is aimed at confirming that a specific batch of a product does not contain a set of substances beyond a particular level. Usually this document is used for legal, commercial, operational, quality compliance.
Cold PourNot to be confused with Cold Throw. Cold Pour is a technique used to pour wax (typically paraffine wax) in cold or very cold metal moulds. Objective is to achieve a rough, irregular, and rustic candle surface. See chatter marks.
Cold ThrowA dimension of candle performance, it describes the strength and intensity of the scent emanated by a candle when not lit. Also known as CT.
Coreless WicksA wick is coreless when the waxed cotton is not braided with support materials like a zinc wire. A coreless wick should be rigid enough to sustain itself. Coreless wicks are usually not recommended for gel candles.
CT Short for Cold Throw, see above.
Cure / Cure TimeThe amount of time required for a poured candle to stabilize, solidify, and reach the expected performance in terms of burn, cold and how scent throw, appearance. Among other things, candle cure or curing time depends on the candle formulation and external environmental factors.
DelaminationAnother name for Wet Spots, see definition.
Double BoilerAlso known as Bain Marie, see relevant voice above.
ECMAThe European Candle Manufacturers Association, ECMA, is the association of the former the former AECM (Association of European Candle Manufacturers) ‎and ECA (European Candle Association), representing the entire European candle industry.
Flash PointThe temperature at which a solid or liquid substance starts emitting gasses that can be ignited.
In candle making this typically refers to liquid wax and the eventual mixed fragrances. This ignition and sustained combustion is what happens when the candle flame melts the wax which in turn emits gas that is then set alight. The Flash Point temperature is shown on your component’s SDS, and is NOT the temperature at which a substance will catch fire in absence of a flame/ignition. That is the Auto Ignition temperature, also shown on SDS if present.
Flash point temperatures should be given particular attention when making scented gel candles. Gel wax typically has a low flash point, and some fragrances could lower it even more.
Flickering FlameAn unsteady flame that burns irregularly. In candle terms, this might be related to wrong sizing of the wick, incorrect blending, untested formulations. A Burn Test might help determine causes and remedies.
Fragrance LoadUsually expressed in percentage, this wax dimension indicated the recommended wax and fragrance proportions to blend.
A wax with a 10% Fragrance Load will be usable to produce a candle that weights 100 grams, 10 grams of which will be of Fragrance and 90 grams will be of wax.
The Fragrance Load is usually indicated for each wax formulation. Adding too much fragrance might result in separation between the wax and the fragrance.
Different fragrances might behave in different ways, so testing is always recommended. Also known as Scent Load
Fragrance OilAn additive for candles, can be natural, synthetic, or a mix. Can be Essential Oil, Infused Oil, etc. Sometimes shortened as FO.
A blend of Fragrance Oils and wax will have specific health and safety implications that need to be reflected in the CLP labels (see above).
FrostingA defect occurring to the surface of candles and wax melts, where some of the surface looks like “frozen” or “crystallized”. This is also known as “bloom” when appearing on the side of pillar candles.
This phenomenon typically happens when the wax has not been melted completely (the wax is not transparent in your melter), or containers and moulds are too cold (not at room temperature or higher). Cooling temperature might also be incorrect. If happening at the top of a candle, frosting can be solved by a Second Pour. Different blends and formulations behave differently, testing might be needed.
Gel CandleA translucent, jelly, clear candle made from a mineral oil-based product.
Glass AdhesionThe ability of a wax to adhere to the wall of its container. This dimension is particularly important for container candles that are poured into transparent containers. Glass Adhesion is determined by the tendency of wax to shrink while cooling, in particular by the speed of the contraction. And it’s affected by environmental, wax and container temperatures, and adjusting those might resolve adhesion issues.
Different wax blends and formulations will show different Glass Adhesion. Very bad Glass Adhesion will generate Wet Spots, see definition.
GutterIn a pillar candle, the melted wax that runs down and then solidifies on the side of the pillar is called “gutter”.
Handling InstructionsA document that details how to use a particular product. While not going into technical details like an SDS or a COA could, the handling instructions often describe what temperatures are most indicated when using a specific product.
Hang UpIn a pillar or container candle, the wax that builds on the side of the pillar/container while the melt pool is completely developed. Large hung ups of wax will produce the phenomenon called “tunnelling”, where the candle is burned around the core and a large quantity of wax is left not burnt. This can be solved by using a larger wick.
Hot ThrowA dimension of candle performance, it describes the strength and intensity of the scent emanated by a candle when lit. Also known as HT.
Hurricane CandleA candle composed by an on outer shell of transparent wax, usually decorated with a range of techniques and not to be lit/melted, and an inner candle that will be lit.
Jump LinesSee Chatter marks
MeltAlso known as Wax Melts, it’s another name for Wax Tarts, see definition.
Melting PointThe temperature at which a substance liquefies.
In candle making, some see the melting point also as an indicator of the ability of a wax to blend with fragrances or of the “hardness” of a wax, and therefore of its suitability for specific candle making uses. This might not always be true, as different formulations will behave differently at specific temperatures.
Melt PoolThe liquid wax that collects around the base of the wick. The size of the melt pool is primarily affected by the type of wick and the melting point of a wax. In a container candle, each burn should be long enough for the melt pool to reach the walls of the container. In a pillar candle, the melt pool should be balanced in a way that most of the liquid wax collects around the wick.
Mix Temperature The recommended temperature of the wax for an optimal blend with fragrance and dye.
MottlingThis effect is purposefully sought by candle makers to produce a “crystalized” finish to their candles.
The irregular appearance of mottled candles differ from frosting as the latter is a local, undesired defect affecting only part of the candle. Mottling affects the candle as a whole. It’s typically an effect for pillar, paraffin dyed candles.
MouldA container used to shape wax melts and wax tarts, pillar, or otherwise freestanding candles. Candle moulds are made of polycarbonate plastic, rubber silicon, metal, and in general non-porous material. Moulds need to allow for easy release of the candle.
Mould ReleaseAn agent that facilitates the separation between the mould and the moulded product, e.g., a pillar candle. Interestingly, wax can be used as a release agent itself in industrial processes.
MSDSMaterial Safety Data Sheet, also known as SDS. It’s the information sheet that accompanies products like waxes and fragrances.
MushroomingAlso known as “mushroom wicking”, mushrooming is an issue created by the wick absorbing more liquid wax than the flame can burn. The result is a build-up on the tip of a wick which looks like a mushroom. The first solutions to be attempted to fix this issue are to test the same candle, at the same conditions, with different wicks.
NCAThe National Candle Association is the trade association representing US candle manufacturers and suppliers and serves as the leading technical authority on candle manufacturing, science, and safety.
Pour Temperature The temperature at which is recommended to pour the melted blend of wax and fragrance into the candle container or mould.
Relief HolesA technique to reduce or eliminate air pockets forming in pillar candles, usually paraffin pillar candles. Relief Holes should not be poked all the way down to the surfaces of the mould, while they might be big enough for wax to flow in if re-poured.
Re-pourAlso known as “second pour”, the re-pour is the process of filling or covering cavities or imperfection appeared during the cool down and shrinkage of the first pour.
RSPORoundtable on Sustainable Palm Oil is a not-for-profit association that unites palm oil industry stakeholders to promote the growth and use of sustainable oil palm products through credible global standards and engagement of stakeholders.
Scent LoadAlso known as Fragrance Load, see definition.
Scent throwUsually differentiated in Cold Throw (unlit candle) and Hot Throw (lit candle), see relevant definitions.
SDS Safety Data Sheet, also known as MSDS (the additional “M” is for “material”). It’s the information sheet that accompanies products like waxes and fragrances.
Second PourAlso known as “Re-pour”, the second pour is the process of filling or covering cavities or imperfection appeared during the cooling down, contraction and shrinkage of the first wax pour.
Sink HoleA defect caused by the wax shrinking and contracting while cooling down. Different waxes can be prone to developing cavities which can appear on the surface of the candle, as well as withing. Normally, sink holes are quickly fixed with a second pour.
Sooting Black residue accumulating on the walls of the candle container. This might be corrected by changing wick.
Stearic AcidAlso known as Stearin, stearic acid can be of sustainable, botanical origin e.g. derived from RSPO palm oil, and it’s used to add opacity to candles, while hardening them.
StearinAnother name for Stearic Acid, see definition.
StutteringSee Chatter marks
Taper CandleThe type of candle that can only be used on a candle holder or chandelier. Taper candles are tall and thin, getting thinner at the top.
TartAnother name for Wax Tarts, see definition.
TDS / Technical SpecificationsTechnical Data Sheet, this document contains some of the specifications of the candles. As opposed to SDS, which are related to safety and therefore always readily available, TDSs might include some commercial secret and are not always made available.
Tealight CandleA specific type of container candle, tealight candles are usually poured in a tin cup measuring approximately 1.5” / 38 mm in diameter and 0.5” / 13 mm tall.
Throw Short for Scent Throw, it’s usually divided in Cold Throw (unlit candle) and Hot Throw (lit candle). See definitions.
Top FinishingA technique consisting in heating the top of a candle, typically a container one once it’s set. Heating melts the wax smoothing out imperfections. The top of the candle can be finished manually with a heat gun, or other heat radiant elements.
Top Pour Another name for Second Pour, see definition.
TunnellingThe issue occurring when the centre of the candle is consumed while its edges are not. The flame effectively “digs a tunnel” through the candle, with a small Melt Pool (see definition) not reaching the container walls and possibly the flame eventually going out. This typically occurs with container candles. The most common cause is incorrect wick size, possibly too small.
UFI Short for Unique Formula Identifier, UFI codes are used around the world to help identify a product in the event of an emergency, e.g., poisoning after ingestion. Local regulations might differ so please investigate if an UFI code is compulsory or not in your area.
UV StabilizerA chemical additive for candles, reduces oxidation and degradation caused by exposure to UV/natural light and therefore prevents colour fading.
VybarA polymer additive for candles, Vybar hardens pillar candles and wax melts/tarts. It facilitates the extraction from moulds, while improving scent throw.
Wax MeltAnother name for Wax Tarts, see definition.
Wax TartAlso known as just Tarts, Melts or Wax Melts, Wax Tarts are small blocks of scented and dyed wax to be used in an oil burner, usually heated by a tea light candle. They are usually made with specific wax formulations.
Wet SpotsA defect of container candles that display irregular contact between the wax and the container walls. Also known as “Delamination”, this issue can be tackled by testing different pouring temperatures as well as container and environmental temperatures.
Wick BarAlso known as wick holder, the Wick Bar is used to keep a wick in position in during the pour of a container candle. The Wick Bar is positioned across container prior to poring wax, and removed once the wax has cooled down.
Wick TabThe base to which the wick filament is attached to.

Picture by Joshua Hoehne – Unsplash

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