How to Make Wax Melts (Clamshells and Molds)

What wax melts are

Wax melts (also called tarts) are small pieces of scented wax with no wick. They go into an electric or tealight warmer, which melts them slowly so the fragrance fills the room. When the scent fades, the used wax comes out and a fresh melt goes in.

Because there is no wick and no melt pool to manage, melts skip the hardest part of candle making: wick sizing. That makes them a good first product, and a quick way to smell how a fragrance oil behaves warm before you commit it to a full candle test.

Choosing a wax for melts

Melts need a wax that sets firm enough to hold a crisp shape and release cleanly from a mold, and that can hold a good amount of fragrance. Soft container waxes are made to cling to glass, so they can be sticky or slumped in a mold. Most suppliers point makers to pillar waxes or waxes sold specifically for melts and tarts.

The fragrance a wax can hold varies a lot by product, which is why the number on your wax’s data sheet matters more than any general rule:

The same seller also publishes a clamshell recipe at 9% and a soy melt recipe at 10%, noting you can go lower to taste. In short: the maximum is set by the wax, and you do not have to use it all.

Clamshells vs silicone molds

Clamshells are the easy start for selling, because the package and the mold are the same thing. Silicone molds give you shapes and gifts, and you can reuse them for years.

How much wax each clamshell or mold holds

Do not guess, and do not trust a size you saw for a different tray. Clamshells and molds come in many sizes. One widely sold standard 6-cavity clamshell with 1-inch cubes is listed by its seller as holding 2.75 oz (78 g) of wax, and the same seller says half a pound of wax fills about three of them. Yours may hold more or less.

Two ways to find out:

1. Weigh a filled one. Pour one clamshell or mold with your wax, let it set, and weigh it minus the empty tray. That is your exact number.
2. Use water first. Fill one cavity (or the whole tray) with water to the line you will pour to, and weigh the water. Wax is lighter than water (soy and paraffin waxes publish a specific gravity around 0.9), so the wax weight will be a little less. The Fill Weight calculator turns that water weight into a wax weight for your wax type.

Then multiply by how many clamshells or molds you are pouring. The Wax Melts calculator accepts either the weight per clamshell or mold, or the number of cavities times the weight of one cavity.

Step by step

Temperatures below are the ones the wax sellers publish for the example waxes. Your wax may differ, so read its data sheet first.

1. Weigh your wax on a digital scale. Work out the batch with the Wax Melts calculator so you know the wax and oil weights before you start.
2. Melt the wax in a pouring pitcher set in a double boiler. Both example waxes list heating to 185°F (85°C).
3. Add the fragrance oil and any dye, weighed, and stir gently for about two minutes so it mixes in fully.
4. Cool to the pour temperature your wax lists. CocoSol lists 170–175°F (77–79°C); IGI 6028 lists 180°F (82°C). Make sure it is no hotter than your clamshell or mold allows.
5. Pour into clean, dry clamshells or molds on a level surface.
6. Let them set fully, overnight is the usual advice, before you close clamshell lids or unmold.
7. Label and cure (next section).

Curing wax melts

Published advice differs here. One supplier’s clamshell recipe only says to let the melts cool overnight before closing them; the same supplier suggests letting soy melts rest 1–2 weeks before use for the best scent. Soy and other natural waxes generally benefit from that rest; test your own wax and oils by smelling melts at a few different ages.

Keep curing melts covered and at room temperature. Clamshells can simply be closed once set.

If you plan to sell them

• Label every package. Put warning and use instructions on the label; with clamshells, one supplier suggests the inside of the lid. See candle label requirements for what US rules ask for, and check your state.
• Tell buyers how to use them: in a warmer, never lit with a flame, and following the warmer maker’s directions.
• Strong scents and small rooms: a high load in a bathroom-sized room can be too much. Say so on your listing if a scent is very strong.
• Price them properly. The Candle Cost & Pricing calculator works for melts too: count the wax, oil, clamshell and label per package.

Melts as a fragrance test

Because melts take a wick out of the picture, they are a quick way to hear how an oil smells warm. Keep in mind that a melt is not a candle test: a melt says nothing about how your candle wick, melt pool or jar will perform. When a scent goes into a candle, it still needs a full burn test.