Hello & welcome..
The differences in the different rayons we have available is small but noticeable to the trained eye.
My ranking is pharmaceutical, balls, CCr
Sally's cellucotton rayon is readily available and cheap. Its the easiest to work with due to its rope style and the largest quantity. It has some small knots randomly. Its rayon and it works as intended.
Graham CelluCotton Cotton Coil
The rayon balls are quality fiber. Better than sallys on a fiber level. Being balls they are not as easy to work with, but once unrolled are nice even strands with no knots. The fiber is slightly better quality, and would have received an extra wash for medical use. More sheen to the fiber than others. The cost is a little higher.
Tidi large rayon balls are great, bigger balls. More fiber per unroll. 1000 large for 15 + 13 shipping.. Its a ton, like a huge box, some pics have been posted before..
TIDI Cotton and Rayon Balls - MedSupplier.com
Delascos medium rayon balls, from consumer catalog. 200 for 3.50 + 7 shipping.
Delasco - Rayon Balls
The pharmaceutical/ bottle rayon is top notch. Possibly the best.. Great quality, even clean fibers. Easy to work with and pure. USP quality. Seems to stay the fluffiest to me. Only good source is the small bottle quantity.
This source dried up.... they changed the packaging..
( Walmart - spring valley meletonin *1mg size has rayon filler.(others don't) Enough for 20+ wicks easily. Great sample to try it out... Even more readily available than Sally's. Theres a Walmart on about every corner now..
Cost - $4.00
http://www.walmart.com/msharbor/ip/15136798?&veh=mweb)