I’ve worked the body of this shawl in both Rowan Fine Art yarn (in pheasant) and ECY Askham 4 ply (in walnut), alternating the rows in each yarn. The border is knitted in ECY Millburn 4 ply Harvest Gold.
I used 50 g of Rowan Artyarn, 50g of Askham 4 ply and 100g of Millburn 4ply. So if you plan on using multiple yarns, do bear in mind the border takes pretty much the same amount of yarn as the whole shawl.
Please let me know if you find any errors in the pattern!

Errata: Row 1 when repeated should read
K3, sm, KFB, knit to marker, sm, K4, sm, knit to last stitch before marker, KFB, sm, K3 (thanks to Purlpeaches for pointing it out!)