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.
| Grade | Name | AFD (Microns) | Use |
|---|---|---|---|
| 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 |
