Microcrystalline waxes are separated from crude oil during the production of heavy lubricating oils. First a high oil product is produced which is called petrolatum; the petrolatum can be further refined as is or deoiled to produce a microcrystalline wax.
Microcrystalline waxes contain much more branching and are of a higher molecular weight than paraffin waxes.
But paraffin waxes and microcrystalline waxes are both carbohydrates, which means they are composed of hydrogen and carbon. The length and type of the carbon chain affect the characteristics of the wax, including its melting point and consistency (soft or hard).
Microcrystalline waxes differ from paraffin waxes because of their higher molecular weight and their very fine crystalline structure (hence their name), which makes them more flexible and gives them interesting stickiness properties.
Their color vary from white to brown and their consistency from soft (microcrystalline soft or micro soft - no joke) to hard (microcrystalline hard or micro hard).Whenever possible, prefer the pellets to the slab conditioning. It's much easier and convenient to work with
Also, and this is a very interesting point for us candlemakers, their melting point is higher than that of paraffin waxes: 130°F to 171°F for micro soft and 185°F to 200°F for micro hard.
Microcrystalline Soft wax is, well, soft, flexible and relatively sticky, which makes it extremely interesting for candlemaking. For instance, it can be added to a Container candle formula, in order to help the wax "stick" to the recipient walls (we'll see in details in another article why this can sometimes be a pain in the ear).
It can also be used, combined with plain paraffin, to facilitate the adhesion when making a multiple layers pillar candle (used in a 1 to 10% proportion, depending on the type of project).
Another use of micro soft is with Cut'n Carve (Or Cut 'n Curl or Dip 'n Carve) candles. These beautiful candles are made by partially cutting off - using a sharp knife or a Stanley - slices of a freshly dipped candle and twist or curl them in various shapes and directions. The stickiness and elasticity of the microcrystalline soft wax make it a good choice for this type of work.
The microcrystalline hard wax is, as the name suggests, harder than the former and has a higher melting point (185°F to 200°F). This latter feature is interesting in many cases.
You'll use it for instance to make the shell of a Hurricane candle or to overdip pillars and tapers to give them a better burning behavior and prevent them from dripping.
Dipping candles into micro hard wax at a specific temperature will give the candles a great snowflake effect.