Connecting threads and Atlanta thread company are both good sources for threads. i have been using the Clover Silk Threads and love them, a great collection of colors and good prices. i think the first silk thread i bought was a YLI; so i have a few of both...the difference...the yli silk is 100 weight (very thin/fine) the clover silk is 50 weight, so a little heavier...other than that they both work the same...oh the yli comes with 200 meters and is made in Japan, the clover comes with 100 meters and is from Germany. cost wise i think they even out. i bought the yli in a 6 spool (kit) from connecting threads. the clover i get at a lqs by the spool