Phlox scarf is a beautiful project thsat can be made using any weight of yarn.
Prototype was made using Hobbii Dahlia Mixo, Fingering weight, #2 (100% Cotton, 874 yards/ 800 m per 7 oz/200g Ball)

Estimated Yardage
680 yards

Hook
US size G (4 mm) Crochet Hook
Gauge
For Sport weight yarn = 18 sts over 12 rows = 4”/10 cm Square made in dc, before blocking.
Adjust hook size if necessary, to obtain gauge.
Note that gauge is not important for this project.