Continuing my topic from Monday....
Yarn weight category This number system lists yarn from 0 (thinnest) to 6 (thickest) according to the American Craft Yarn Council
Standard Yarn Weight System. It also lists the common names used internationally for
the various yarn weights in North America. Many knitters feel there is
too much overlap in the system since many yarns fall into 2 categories.
This can be valuable information since as an example the results between 3 and 4 ply fingering weights can be significantly different. Some countries use ply labels instead of names or numbers. You can see a comparison chart here from Ravelry.
Wraps Per Inch
Many knitters love having this information available. I personally am not fond of this system. I've tried wrapping and I notice soft or lofty yarns can give different counts with each subsequent wrapping test. On the other hand if you have no information at all on a yarn it can be a good starting point. You can go here for a chart with wraps/gauge/weight information.
Country of origin
The label may indicate this information but consumers should know it could mean where the fibre came from or where it was processed. As distributors are impacted by the ethical fashion movement they are quick to greenwash the information based on the media bias of the moment. Many fibres move through a chain of processing that can route it through a number of countries before it shows up at your local shop.
This gives details for washing, drying, ironing, and dry cleaning directions if applicable. For more details on what each symbol means, click here to view the Lion Brand care page. It's a particularly comprehensive list of the symbols. If you doubt the information provided use your swatch to test cleaning methods.
Colour Number or Name and Dye Lot
Not only does this area
include the yarn color’s name and number, but it also includes the dye
lot. If you’re buying more than one skein of the same yarn, make sure
that your dye lot numbers all match. Sometimes the same yarn color will
vary slightly between dye lots, so you should always check this number. Yarn shop owners also report that mislabeling can occur.
The address of the company and a web site may appear on the label.
Number of balls or skeins for a garment
I really liked having this information in the past, unfortunately it seems to have been dropped from current labels. It appeared as a sweater outline with a number in the centre. The sweater would show either long or short sleeves and would give a average size chest measurement for the knitter to extrapolate up or down depending on their sizing requirements.