Wednesday, January 2, 2013

Jar sizes, product amounts, and such. A tiny note from the Chemist.

Oddly, we get frequent inquiries about the size differences in products, most often the loose eye shadow. The sizes and weights noted in the catalogue are correct. Though the weights are sometimes a little understated. The weight of a mini jar of eye shadow is about half a gram, usually a tiny bit more. But the measurement is always the same: one-third (1/3) of a teaspoon, or 1/4tsp for Arcanes. Some may appear a smidgen more full than others when on their sides, due to density of ingredients and/or particle size, which I'll get to on later in this post. They're not blindly filled; we have measures for filling. The full size, however, are filled to the top, packed down, and topped off. This is how it often seems the Mini jars give about 1/3 or more of the size of a full jar.

The size of jars for Minis (these are most certainly not samples! A sample doesn't customarily last you weeks to months. They're small versions of the product) is notably smaller than the full size. The regular eye shadow jars, a common size, hold just about 5ml of liquid, while the Mini size holds 3ml. Below are comparison photos of the product and jars.





The weight for Fyrinnae's loose eye shadow is listed on the store and labels as approximately 3 grams. Some are close to 2.8, and many are over 3.5g. The US labeling regulations allow a very small variance in weight, usually if it may vary between shades or styles of the same product. For the Minis, we have it listed as .4 to .7gram. That's not quite correct, as the 1/3tsp of product weights a tiny bit more than that, but understating is always a bit better policy. You're still receiving the same amount, even if by weight it may be .5g for Cupcake Frosting, and .9g for Dragon's Wing.


Still with me here? Cool, as I'm going to keep typing. Let's discuss why some weigh more. In short, some colourants (pure dry powders in the form of dyes, inorganic pigments, micas, synthetic fluorphlogopite and silicates, etc) are much heavier than others. Chromium Oxide weights a lot more, and is far more dense, than standard cosmetic grade lake dyes. So for example, if a green eye shadow is based on chromium oxide for main colour and treated 10-25µm mica for shimmer and depth, it may weigh twice as much as a similar colour shadow based on blue 1, yellow 5, titanium dioxide, and 50-100µm sparkle mica. Make sense? The product appears the same size, and you get the same amount of product, but the weight varies. Most of the time it's not noticeable.

Now, that probably explained why the same size jar from X company is marked as a different weight than the same size container from Z company. Neither company is wrong, but X uses a smaller particle size borosilicate (40-150µm) for sparkle, and a considerable amount of stearates and iron oxide in their base, creating some rich opaque colours. This makes the jar net weight 4.5 grams (or whatever, I'm making this up as I type). Z contracts a manufacturer to produce a vivid product using dyes and treated mica, with big sparkle (100-350µm), in some of their shades. These jars are the same size as X's, but net weight of product is 2 grams. Consumers are not being cheated, company is not lying, but ingredients have varying weights. This applies for all cosmetic products, be they powder, creme, liquid, or wax based. Think of a bucket of sand versus a bucket of Legos. Besides the fact neither would be fun dumped across your living room floor, the Lego bucket will weigh less, even though both are filled to the top.

WHAT is µm?? That's the symbol for micrometre. That's how we measure the particle size in powders. An average shimmery mica colourant has a µm range of 5 to 100. The larger the number, the more sparkle (like 200-300), until we get past general cosmetic use and into nail polish (huge flakes of silicate and synthetic mica!). Smaller numbers such as 5 to 10 are most often in the satin and low-shimmer products, where you have a sheen but no sparkle.