The fabric is a medium weight woven which emphasises the silhouette of the Kielo in a way I really like. I cut a straight size 10, reduced the length (by 9 inches) and consequently increased the height of the vent. The only slightly fiddly step was finishing the armholes, I finished my armholes with narrow hems and they turned out fine, but obviously hemming (or attaching bias binding) on a curved area can be a bit fiddly.
More info on my blog: https://englishgirlathome.com/2019/08/01/woven-kielo/