Another Johnny Was fan here. That embroidery is gorgeous and so well done!
I would say their clothing runs pretty much true to size, maybe a little on the larger side. I like to wash, rather than dry clean and there is usually a bit of shrinkage. Tbe rayon washes great by the way, and many times rayon comes out looking like a shrunkage mess with other brands.
That being said, I have a beautiful velvet jacket from them that ran huge, so I would order a size down in that type of item.
I recently ordered a deep melon linen long sleeve top. Haven't received it yet. They were having a nice sale. Maybe they still are (?).