I am often asked as a skirter/sorter/grader on what is the best use for a particular micron count. Here are the ranges I sort/grade into and their best use.
The human eye can only see about a 2 micron difference, so of course this is a guide and the more you sort, the better you become at sorting. The key is to have batches of fiber of no more than 3 micron difference or more than 1/2 inch difference in staple length for the best yarn.
This is my chart that I developed over the years and is pretty typical of commercial grading. Please DO NOT copy the chart. You may link to the post or refer to it for personal use.
I made a cheat sheet years ago by starting with OFDA tested fiber in different microns and have that sheet with the representative fiber sitting next to me as a guide when I grade.
Fiber that has a lot of guard hair that is markedly different than the primaries in micron is batched differently and not mixed with the pure grades.
|1||Ultra Fine (Royal Baby)||less than 20||Next to skin items, gentle use|
|2||Super Fine (Baby)||20-22.9||Gentle use items – shawls and baby items|
|3||Fine||23-25.9||Most versatile grade - pretty much anything wearable|
|4||Medium||26-28.9||Socks, throws, outerwear and felt|
|5||Intermediate||29-32||Quilt Batting, duvets, outerwear and felt|
|6||Robust||greater than 32||Batting, insulation and rugs|