Superior Bottom Line vs Aurifil 50wt Thread — Poly vs Cotton Compared

Superior Threads Bottom Line (polyester, 60wt) and Aurifil 50wt (cotton) are both fine, lightweight threads popular with quilters — but they're designed for different things. Here's how to decide which belongs in your machine.

Linda's Electric Quilters Expert Comparison

Superior Threads Bottom Line

SKU: BL-628

$13.59 / cone

60 wt polyester • 3,000 yards • Lint-free • Ultra-fine • Matte finish

Shop Bottom Line

Aurifil 50wt Cotton Thread

SKU: MK50SP1100

$14.75 / spool

50 wt cotton • 1,422 yards • Slight sheen • Natural cotton feel • 270+ colors

Shop Aurifil

Head-to-Head Comparison

Feature	Bottom Line	Aurifil 50wt
Fiber	100% polyester Bottom Line	100% cotton Aurifil
Weight	60 wt (finer) Bottom Line	50 wt
Yardage	3,000 yds Bottom Line	1,422 yds
Price per yard	$0.0045/yd Bottom Line	$0.010/yd
Lint	Lint-free Bottom Line	Some cotton lint
Cotton feel/look	Matte poly	Natural cotton sheen Aurifil
Color range	50+ colors	270+ colors Aurifil
Best for cotton fabrics	Good	Excellent — natural pairing Aurifil
Bobbin use	Outstanding Bottom Line	Good

▶ Our VerdictBottom Line wins on value — lower cost per yard, lint-free, and outstanding in the bobbin. Aurifil 50wt is the premium cotton choice: a vastly larger color palette, a natural cotton look that pairs beautifully with cotton fabric, and the preferred thread of many quilt designers and guild quilters. Choose by fiber philosophy and color needs.

Who Should Choose Which?

Choose Bottom Line if you…

Want an invisible or blending bobbin thread
Prefer lint-free polyester
Run a longarm business watching cost per quilt
Want maximum yardage per cone

Choose Aurifil 50wt if you…

Want cotton thread on cotton quilts
Need a specific color match (270+ choices)
Make show quilts or art quilts
Do domestic machine quilting or EPP
Prefer cotton fiber philosophy

Frequently Asked Questions

Which thread is better for hand quilting?

Aurifil 50wt cotton — the natural fiber feel and the way it moves through fabric makes it a favorite for hand quilting. Bottom Line is designed for machine use.

Can I use Aurifil 50wt on a longarm?

Yes — Aurifil 50wt works on a longarm. Just be aware it produces slightly more lint than polyester, so clean your machine more frequently.

Why does Aurifil cost more per yard?

The large spool holds only 1,422 yards vs 3,000 for Bottom Line, and cotton commands a higher price than polyester. You're also paying for the Italian manufacturing quality and color range.

Shop Fine Thread at Linda's Electric Quilters

Expert longarm advice • Trusted since 1999

Shop Bottom Line Shop Aurifil All Thread