You can use whatever yarn you like and use the gauge you feel comfortable with. The total amount of yarn is totally up to you as well. The scarf and the shawl in this pattern are just two examples showing the scarf with different gauges and different yarn qualities. The pattern is designed to be flexible regarding your choice of size and amount of yarn. Therefor, the scarf and shawl are worked similarly and only differs in shawl being a large garment and the scarf being a small garment. The scarf is worked the same either way. When I worked the scarf, I used a tip on a smoother bind off.

Sizes
Scarf (small) and Shawl (large).

Measurements (after wash)
Measurements depend on the yarn used and the blocking.
Scarf: approx. 115 cm | 45.3 in.
Shawl: approx. 200 cm | 78.7 in.

Suggested yarn
Scarf: Cashmere Premium by Lang Yarns (25g/115m).
Shawl: Baby Alpaca by Lang Yarns (50g/170m)

Gauge (after wash and blocking)
Scarf: 22-24/10 in stockinette stitch using 3,5 mm (US4) needles.
Shawl: 20/10 in stockinette stitch using 5 mm (US8) needles (the yarn is held double).

The gauge does not necessarily have to be perfect since you can easily adjust to the desired size or until you have used the first half of your yarn.

Suggested yarn amount
Scarf (cashmere): 45 grams (2 skeins).
Shawl (baby alpaca): 300 grams (6 skeins)

Suggested needles + notions
Cashmere premium: Circular needles 3,5 mm (US4), 40-60 cm | 16-24 in.
Baby Alpaca: Circular needles 5 mm (US8), 60 cm | 24 in (the yarn is held double).

Workflow
The scarf is worked flat from tip to tip.