Aurifil is in a class by itself. There are 2 main reasons why most people like it: it's very low lint so less maintenance for your machine, and it's 2-ply making it easier to do more precision piecing.
Here are the other reasons I love it:
- they use
extra long staple cotton instead of long staple cotton. that makes a stronger thread that is less prone to breaking (also, combined with the mercerizing process that makes it the ultra low lint).
- Extra long staple Egyptian cotton is the best cotton there is & within that category, Aurifil only buys the XL variety that is the highest rated (cotton is rated similar to beef; Aurifil buys the equivalent of Grade A)
- the 2-ply thread is twisted rather than braided, resulting in less pressure on each of the plies, which is supposed to make each ply less prone to breaking/splitting/fraying/weakening
- 2-ply generally means I get more thread per spool, resulting in a cost that isn't that much more than Gutermann or other decent-but-not-as-good brands
- 2-ply thread means I can use a size 70/10 needle with 50wt, or 80/12 needle with 28 & 40wt, resulting in smaller holes for quilting (& piecing)
- it comes in 270+ different colors
- all 270 colors are available in 50, 40, 28 & 12wt, and their 6-strand floss
- their dying process is the leader in the industry. it is almost entirely automated, resulting in great consistency with the solid colors (variegated threads are not consistent because the multi-color ones are printed, not dyed & the multi-shade/single-color ones are sand-blasted to remove some of the color [lighten] and the sand goes where it wills). No process is perfect & it depends in part upon the cotton itself, but from one year to the next, Aurifil thread colors are very consistent when stored in similar conditions
- on the large size spools (1100-1300m), the cap comes off the end, so when I put it on my machine, there is nowhere for the thread to puddle/wrap around/get caught. it's a small benefit, but I've had issues with that on other brands so I do appreciate that little touch
And finally, check out this link to see what different threads look like under a microscope:
http://owensolivia.blogspot.com/2012...icroscope.html