Quick answer

For most longarm quilting, So Fine! #50 offers a balanced blend of strength and smoothness, while The Bottom Line #654 excels when you need a finer, nearly invisible stitch or want to reduce bulk in the seam.

Weight and ply matter for stitch appearance

Thread weight and ply directly affect how visible your stitches are and how the thread behaves on the machine. So Fine! is a 50 wt 3-ply thread, making it slightly thicker and more durable. The Bottom Line is a 60 wt 2-ply thread, which is finer and lighter, ideal for delicate work or when you want the thread to blend into the fabric.

Strength and tension considerations

A 3-ply thread like So Fine! generally resists breaking under tension better than a 2-ply thread, which is important for longarm quilting where the thread is under constant stress. However, The Bottom Line's finer diameter means it can be easier to bury knots and may cause less thread buildup in dense quilting areas.

Lint and machine maintenance

Both threads are advertised as lint-free, which is a key feature for longarm machines where lint can cause tension issues and require more frequent cleaning. You can expect less downtime with either option compared to standard all-purpose threads.

Trade-offs at a glance

  • So Fine! #50 (50 wt 3-ply): Stronger and more durable, suitable for high-tension longarm quilting. Slightly thicker stitch stands out more.
  • The Bottom Line #654 (60 wt 2-ply): Finer and lighter, nearly invisible stitch. Easier to bury knots and reduces bulk in dense quilting areas.
  • Lint performance: Both are lint-free polyester, minimizing machine maintenance and tension issues compared to cotton or blended threads.

Product facts at a glance

  • The Bottom Line #654 Oatmeal: The Bottom Line #654 Oatmeal is a 60 wt 2-ply lint-free polyester thread with 3,000 yards per cone. Its finer weight and 2-ply construction make it ideal for invisible stitches, bobbin work, or reducing bulk in seams.

    The Bottom Line #654 Oatmeal

    The Bottom Line #654 Oatmeal

  • So Fine! Thread #479 Mountain Man: So Fine! Thread #479 Mountain Man is a 50 wt 3-ply lint-free polyester thread with 3,280 yards per cone. The heavier 3-ply build provides extra strength for longarm quilting and a slightly more pronounced stitch that shows up beautifully on solid fabrics.

    So Fine! Thread #479 Mountain Man

    So Fine! Thread #479 Mountain Man

Which thread fits your project?

Best for

  • Longarm quilters who want a strong, visible stitch that holds up under tension and works well on solid fabrics
  • Projects where you need a fine, subtle thread that blends into the fabric or reduces bulk in dense stitching areas

Not for

  • Quilters who need a single thread for both top and bobbin with very different weight requirements (consider a dedicated bobbin thread)
  • Projects requiring a heavy-duty or metallic thread for decorative effect