How to Read Yarn Labels
A yarn label has tons of vital information. But you need to know how to read the yarn label to understand what information it offers. Pay particular attention to
Gauge (how many stitches and rows per inch) and suggested needle size: This information gives you an idea of what the final knitted fabric will look like. For example, a size US 11 (7 1/2 mm) needle and a gauge of low numbers will yield a heavy, chunky fabric.
Fiber content: Lets you know whether the yarn is wool, cotton, acrylic, a blend, or something else.
Care: If you intend to make a washable garment, check to see whether the yarn is machine- or hand-washable or strictly a dry-clean fiber.
Dye lot number and/or color number: What batch of dye this yarn came from. When you buy multiple skeins of yarn, compare these numbers to ensure that they’re the same (that is, that all your yarn comes from the same dye batch).
To avoid unwanted color variations, buy enough yarn from the same dye lot at one time to complete your project. If you have to buy more later, you may not be able to find yarn from the right dye lot.
Even if you can’t detect a difference in color between two balls of different dye lots, chances are the difference will become apparent when you knit them up one after the other.