What's the difference between the Sulky 30 weight and 12 weight Cotton Threads?

The heavier 12 wt. Cotton is a dramatic looking top thread in both the Solid Colors and the Cotton Blendables. We generally recommend using the 12 wt. on the top (although it is used for bobbin-work as well), and the matching, lighter 30 Wt. in the bobbin.

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Also the 12 wt. solid colors and 30 of the 12 wt. Blendables are now available in the 50-yd. Petites spools, perfect for handwork or small projects.